A while ago I noticed that pop-up org-capture frames are not rendered
(no buffer or mode-line text is shown, as in attached image) when the
window manager forces them to be full screen (floating frames are
rendered as usual).

The issue seems to be triggered by the combination of
maximised frame, frame-resize-pixelwise 't, custom-setting a certain
default font, and loading certain colour theme.
The minimum emacs -Q config, which reproduces the issue in my system
(with my set of installed fonts) is the following:

#+begin_src emacs-lisp
(eval-and-compile
  (defvar bootstrap-version)
  (let ((bootstrap-file
	 (expand-file-name "straight/repos/straight.el/bootstrap.el" user-emacs-directory))
	(bootstrap-version 5))
    (unless (file-exists-p bootstrap-file)
      (with-current-buffer
	  (url-retrieve-synchronously
	   "https://raw.githubusercontent.com/raxod502/straight.el/develop/install.el"
	   'silent 'inhibit-cookies)
	(goto-char (point-max))
	(eval-print-last-sexp)))
    (load bootstrap-file nil 'nomessage)))

(eval-and-compile (straight-use-package 'use-package))

;; Using this instead of custom-set-faces does not trigger the rendering problem
;; (set-face-attribute 'default nil
;; 			  :foundry "adobe"
;; 			  :family "source code pro")
(custom-set-faces
 '(default ((t (:foundry "adobe" :family "source code pro"))))
)


(setq frame-resize-pixelwise t)

(use-package flatui-theme
  :straight t
  :config
  (load-theme 'flatui t))

;; I once managed to narrow down the issue to setting this font from
;; flatui, but it turned out to be not reproducible. Other time, another
;; font setting caused a maximised frame to be not rendered. The only
;; reliable way I can reproduce the issue on my system is lading the
;; whole flatui theme.
;; (custom-set-faces
;;  '(menu ((t (:foreground "#2c3e50" :background "#dfe4ea"))))
;; )
#+end_src

I am not sure if this is something to deal with my system font
configuration or it is emacs specific.
Can someone try to reproduce?

Regards,
Ihor