You can get Ptyxis on Flathub now if you would like to run the stable version rather than Nightly. Unless you’re interested in helping QA Ptyxis or contributing that is probably the Flatpak you want to have installed.
Nightly builds of Ptyxis use the GNOME Nightly SDK meaning GTK from main (or close to it). Living on “trunk” can be a bit painful when it goes through major transitions like is happening now with a move to Vulkan-by-default.
Enjoy!