After upgrading to Plus on Android, a few apps no longer work at all, such as Plex with killswitch enabled

Hey,
Apparently, you cannot reach local resources because you’ve most likely set a dns other than your standard dns. You should be able to reach their IPs anyway. Big companies like Tinder and Plex tend to block data center IPs hence that might not work using VPN either.
Can you try to use the standard DNS or blokada cloud to be able to reach local resources?