About a week and a half back, Jerboa on the Play Store received an update that added 0.18 support and started displaying a similar message whenever you logged in, but didn't actually block using the app or posting, but certain features were not working correctly.
As of the update yesterday, Jerboa crashes unceremoniously if you happen to be previously logged in on lemmy.blahaj.zone, and prevents fresh login with the message above.
I'm a bit worried about how the Jerboa devs are handling updates ☹️
They do have their hands full with everything going on with Lemmy. I think this app looks the best but there's a lot of other options to use while the kinks get worked out.