Parallels 26.3.3, macOS 15.7.7, Ubuntu 26.04, MBP 11,2 After installation and settiing screen resolution to 1920x1200 (16:10) (native retina resolution is 2880x1800 16:10) I'm observing flickering effects within windows, e.g. in Firefox, also in the Terminal app. And also in system windows like "Display Settings".
Parallels 26.4.0, macOS 15.7.7, Ubuntu 26.04 (Kernel 7.0.0), Desktop Mac (Intel) same - flickering effects within windows (Nautilus file manager, PDF viewer,...) at full 4K.