If you are on Windows you can try changing the tablet driver in Preferences to see if it maybe helps. Other than that there are input dynamics settings in the Global Tools panel (top right) which allow tweaking of tablet pen settings.
novhack
Creator of
Recent community posts
You can change some keyboard shortcuts in Edit>Preferences>Shortcuts by selecting a Custom preset. Rebind Pencil tool to any key you want.
You can also change the background look and behaviour in Edit>Preferences>Canvas. Just select Follow Canvas Movement so it behaves like you expected it to behave.
You go to Export -> Animation tab and then under the preview there is a selector which allows you to select "All frames as a single file animation". My general advice would be to use it only for smaller sized canvases with lower amount of frames because it will take a lot of time to export. If you want to do a huge animation then rather export frames as multiple files and use some online tool to create a gif from them. https://ezgif.com/maker
This sounds like a Flatpak sandboxing. Flatpak has a feature that it installs every app separately and sets up permissions very strictly so they cannot potentially damage your system. If that's the case you have to add something like "--filesystem=host" when launching Pixelorama.
https://docs.flatpak.org/en/latest/sandbox-permissions.html