Looks like the original repo of syncthing-android, (https://github.com/Catfriend1/syncthing-android), which was maintained by @Catfriend1, now redirects to the one maintained by @researchxxl (https://github.com/researchxxl/syncthing-android).
The problem seems to be that no one in the syncthing community knows who @researchxxl is. The account was created only 3 weeks ago. There was no communication about how the transfer took place. Was the transfer actually authorized? Did @Catfriend1 get hacked? People are worried about a backdoor hijack attack similar to the XZ libary.
There's a long discussion at https://forum.syncthing.net/t/does-anyone-know-why-syncthing.... It is too long and complex for me to follow. (I tried to get an LLM to summarize that thread for me, but the output was not helpful.)
It is unclear what sycnthing-android users are supposed to do right now. I am staying at version 1.30.0.4 until things become more clear.