Do you know about Flatseal? It’s an application that lets you manage flatpak permissions. Until the portals system is fully working, weakening the sandboxing using Flatseal is what a lot of people do to make the apps work correctly.
Also, if you use KDE, the settings app has flatseal-like functionality built in.
But with the way the Reddit admins are handling the website, you wouldn’t have had that sub for much longer anyway. That’s the whole point of the blackout in the first place. Don’t blame the protesters. Blame the admins. They’re the ones with the power to change things.