The thing about snaps and app image is they are containerized.
Unlike snaps and flatpaks, AppImages arent containerized or sandboxed at all. They are only used to bundle (some) dependencies, so you don't need to rely on packages provided by your distro's package manager.
Because of the sandboxing, once you close the app it stops running in the background therefore there is nothing to get notifications from.
This can't be caused by the sandboxing per se. I use many flatpak apps that keep running if you close all windows, eg. Amberol, Discord.
I don't know if snap/Ubuntu has a “feature” that disables this behaviour
It's also worth mentioning Universal Blue which is based on Fedora Silverblue but has multiple variants with additional doftware. It seems like you can rebase an existing Silverblue system to it and also switch back without reinstallation.
ForgeFed is an ActivityPub Extension to allow cross-forge (git server) issues, pull requests etc. without having to create an account on each server. Forgejo (a Gitea soft-fork) is actively working on this integration.
It's pretty much back to the behavior explained above. If you slightly move your fingers before zooming in, you are stuck at flicking the image away and can't zoom.
Just FYI, the account that you mentioned (@firefox) is actually the lemmy community !firefox@lemmy.ml. This resulted in your toot appearing as a post in that community on lemmy.
Since mastodon has no equivalent to lemmy's communities, it can't handle lemmy's !community@instance links.
Communities are represented as a regular user on the mastodon side, if you mention a user (using @) on mastodon, it will be parsed as a markdown link on lemmy: [@lucy_idk](https://mastodon.world/@lucy_idk)
Unlike snaps and flatpaks, AppImages arent containerized or sandboxed at all. They are only used to bundle (some) dependencies, so you don't need to rely on packages provided by your distro's package manager.
This can't be caused by the sandboxing per se. I use many flatpak apps that keep running if you close all windows, eg. Amberol, Discord.
I don't know if snap/Ubuntu has a “feature” that disables this behaviour