Jira Server app (which is still beta or preview i guess) has updated today and now it says our Jira Server 8.2 is not supported. And it says we should update to 8.3. But Jira 8.3 is not out yet. The help article says that you need 8.1+ though. I have updated Mobile Plugin on the server.
So, upgrading Jira and installing mobile plugin, all for nothing, when after an app update you are cut off. I know, this is beta and all, but i wish i didn't invest so much time into making it work, to have it broken now.