@swisskoala Anbox has been removed from Ubuntu Touch root file system image some times ago.
It has been "somehow" replaced by WayDroid for devices that run Halium 9 and < hardware under-layer. Meizu pro5 is unfortunately not supported by WayDroid.
To completely remove Anbox:
From Android settings remove all your apps.
In terminal:
anbox-tool disable sudo rm -rf ~/anbox-data/ ~/.local/share/applications/anbox/ There are desktop files named anbox at: ~/.local/share/applicationswhich you can delete the apps on the drawer.
Then reboot your device. You may have to wait for the next OTA, or reinstall Ubuntu Touch (do not check wipe option) with the UBports Installer to put back your device in a fully functional state.