Plastic when running into conflicts will often attempt to automerge files. This is fine for code, but sometimes it detects conflicts in prefabs or scene files and tries to resolve those, but this often fails and causes problems. It would be better for those conflicts to be resolved manually.
Is there a way to disable auto conflict resolving, or to disable auto conflict resolving for specific types of files?
In the options panel, you can disable the automatic conflict resolution for everything.
It will affect every file, so if you change tons of files it will probably make merges slower: