I am seeing this issue on emacs head. The text randomly flips vertically. Very hard to reproduce. But if you open a very long C/C++ file like https://github.com/KhronosGroup/Vulkan-Headers/blob/master/include/vulkan/vulkan_core.h and keep moving around the buffer, cut 100ish lines and paste in another location and then move around again. You might hit the issue.
Here is a screenshot of it. I haven’t tried with emacs -Q yet but happy to try if required.
//Wasim
In GNU Emacs 28.0.50 (build 1, x86_64-apple-darwin19.4.0, NS appkit-1894.40 Version 10.15.4 (Build 19E287)) of 2020-05-06 built on Wasims-iMac-Pro.local Repository revision: 86fef6ab89ee54c6f78bc2064e55c5439e929827 Repository branch: master Windowing system distributor 'Apple', version 10.3.1894 System Description: Mac OS X 10.15.4
Recent messages: Source file ‘/Users/wasimabbas/.emacs.d/init.el’ newer than byte-compiled file; using older file Turn on helm-projectile key bindings [yas] Prepared just-in-time loading of snippets successfully. [2 times] You appear to be setting environment variables ("PATH") in your .bashrc or .zshrc: those files are only read by interactive shells, so you should instead set environment variables in startup files like .profile, .bash_profile or .zshenv. Refer to your shell’s man page for more info. Customize ‘exec-path-from-shell-arguments’ to remove "-i" when done, or disable ‘exec-path-from-shell-check-startup-files’ to disable this message. Warning: /Users/wasimabbas/.emacs.d/init.el is newer than /Users/wasimabbas/.emacs.d/init.elc For information about GNU Emacs and the GNU system, type C-h C-a.
Important settings: value of $LANG: en_GB.UTF-8 locale-coding-system: utf-8-unix
Major mode: Lisp Interaction
Minor modes in effect: which-key-mode: t save-place-mode: t global-hl-line-mode: t show-paren-mode: t yas-global-mode: t yas-minor-mode: t pyvenv-mode: t projectile-mode: t helm-mode: t async-bytecomp-package-mode: t helm-autoresize-mode: t helm--remap-mouse-mode: t global-display-line-numbers-mode: t display-line-numbers-mode: t global-evil-mc-mode: t evil-mc-mode: t global-evil-surround-mode: t evil-surround-mode: t evil-leader-mode: t global-evil-search-highlight-persist: t evil-search-highlight-persist: t global-undo-tree-mode: t undo-tree-mode: t shell-dirtrack-mode: t evil-mode: t evil-local-mode: t flycheck-pos-tip-mode: t global-flycheck-mode: t flycheck-mode: t global-company-mode: t company-mode: t tooltip-mode: t global-eldoc-mode: t eldoc-mode: t electric-indent-mode: t mouse-wheel-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t