Reproduction steps:
- emacs -Q
- Evaluate this expression:
  (add-to-list 'default-frame-alist '(internal-border-width . 10))
- Create a new frame (C-x 5 2)
- Create a new tab (C-x t 2)
- Wait a second or start typing

Results:
The tab bar gets cut in half by the area where text is.
Switching tabs flashes the tab bar the way it's supposed to look like for a split second.


In GNU Emacs 29.0.92 (build 1, x86_64-pc-linux-gnu, GTK+ Version
3.24.37, cairo version 1.16.0)
System Description: Guix System

Configured using:
 'configure
 CONFIG_SHELL=/gnu/store/rib9g2ig1xf3kclyl076w28parmncg4k-bash-minimal-5.1.16/bin/bash
 SHELL=/gnu/store/rib9g2ig1xf3kclyl076w28parmncg4k-bash-minimal-5.1.16/bin/bash
 --prefix=/gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92
 --enable-fast-install --with-pgtk --with-modules --with-cairo
 --with-native-compilation --disable-build-details'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP
NOTIFY INOTIFY PDUMPER PGTK PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER XIM GTK3 ZLIB

Important settings:
  value of $EMACSLOADPATH: /gnu/store/kjwa528fiv1bqlx11d9mh7r60ml4fsql-profile/share/emacs/site-lisp:/home/geri/.guix-home/profile/share/emacs/site-lisp:/gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp
  value of $LANG: en_US.utf8
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  tab-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
/gnu/store/kjwa528fiv1bqlx11d9mh7r60ml4fsql-profile/share/emacs/site-lisp/guix-emacs hides /home/geri/.guix-home/profile/share/emacs/site-lisp/guix-emacs
/gnu/store/kjwa528fiv1bqlx11d9mh7r60ml4fsql-profile/share/emacs/site-lisp/site-start hides /home/geri/.guix-home/profile/share/emacs/site-lisp/site-start
/gnu/store/j1qf5zl8pysg608l7szwan0qk25925wg-emacs-transient-0.4.1/share/emacs/site-lisp/transient-0.4.1/transient hides /gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp/transient
/gnu/store/r5w8fq8jznd21r8pzcvb0xb1zxl6y2sc-emacs-use-package-2.4.4/share/emacs/site-lisp/use-package-2.4.4/use-package-lint hides /gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp/use-package/use-package-lint
/gnu/store/r5w8fq8jznd21r8pzcvb0xb1zxl6y2sc-emacs-use-package-2.4.4/share/emacs/site-lisp/use-package-2.4.4/use-package-ensure hides /gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp/use-package/use-package-ensure
/gnu/store/r5w8fq8jznd21r8pzcvb0xb1zxl6y2sc-emacs-use-package-2.4.4/share/emacs/site-lisp/use-package-2.4.4/use-package hides /gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp/use-package/use-package
/gnu/store/r5w8fq8jznd21r8pzcvb0xb1zxl6y2sc-emacs-use-package-2.4.4/share/emacs/site-lisp/use-package-2.4.4/use-package-core hides /gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp/use-package/use-package-core
/gnu/store/r5w8fq8jznd21r8pzcvb0xb1zxl6y2sc-emacs-use-package-2.4.4/share/emacs/site-lisp/use-package-2.4.4/use-package-ensure-system-package hides /gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp/use-package/use-package-ensure-system-package
/gnu/store/r5w8fq8jznd21r8pzcvb0xb1zxl6y2sc-emacs-use-package-2.4.4/share/emacs/site-lisp/use-package-2.4.4/bind-key hides /gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp/use-package/bind-key
/gnu/store/r5w8fq8jznd21r8pzcvb0xb1zxl6y2sc-emacs-use-package-2.4.4/share/emacs/site-lisp/use-package-2.4.4/use-package-jump hides /gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp/use-package/use-package-jump
/gnu/store/r5w8fq8jznd21r8pzcvb0xb1zxl6y2sc-emacs-use-package-2.4.4/share/emacs/site-lisp/use-package-2.4.4/use-package-bind-key hides /gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp/use-package/use-package-bind-key
/gnu/store/r5w8fq8jznd21r8pzcvb0xb1zxl6y2sc-emacs-use-package-2.4.4/share/emacs/site-lisp/use-package-2.4.4/use-package-delight hides /gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp/use-package/use-package-delight
/gnu/store/r5w8fq8jznd21r8pzcvb0xb1zxl6y2sc-emacs-use-package-2.4.4/share/emacs/site-lisp/use-package-2.4.4/use-package-diminish hides /gnu/store/ilmaczmnssmxir9qlqsg6hrp26xa8n5s-emacs-next-pgtk-29.0.92/share/emacs/29.0.92/lisp/use-package/use-package-diminish

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
epg-config gnus-util text-property-search time-date mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail
rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils cl-loaddefs
comp comp-cstr warnings icons subr-x rx cl-seq cl-macs gv cl-extra
help-mode bytecomp byte-compile cl-lib rmc iso-transl tooltip cconv
eldoc paren electric uniquify ediff-hook vc-hooks lisp-float-type
elisp-mode mwheel term/pgtk-win pgtk-win term/common-win pgtk-dnd
tool-bar dnd fontset image regexp-opt fringe tabulated-list replace
newcomment text-mode lisp-mode prog-mode register page tab-bar menu-bar
rfn-eshadow isearch easymenu timer select scroll-bar mouse jit-lock
font-lock syntax font-core term/tty-colors frame minibuffer nadvice seq
simple cl-generic indonesian philippine cham georgian utf-8-lang
misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms
cp51932 hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese composite emoji-zwj charscript charprop case-table
epa-hook jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button
loaddefs theme-loaddefs faces cus-face macroexp files window
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget keymap hashtable-print-readable backquote threads dbusbind
inotify dynamic-setting system-font-setting font-render-setting cairo
gtk pgtk lcms2 multi-tty make-network-process native-compile emacs)

Memory information:
((conses 16 79840 9116)
 (symbols 48 7113 0)
 (strings 32 19750 1857)
 (string-bytes 1 635958)
 (vectors 16 16908)
 (vector-slots 8 341661 7976)
 (floats 8 33 25)
 (intervals 56 492 55)
 (buffers 984 12))