Assuming you're talking about Catfriend1 giving up on syncthing-fork?
Install version 2.0.11.2. This was the last version of it under control of CatFriend1. Just scroll down a bit on the F-Droid page and tap on the version you want to install. And then toggle "ignore new versions". There's a competing Android client made by nel0x who's been maintaining the Google Play version. I'm waiting for them to release more updates. They seen to have a good rep in the Syncthing community.