Google desindexing redirections

Hello, I’ve installed RM the 13 of january. From this time I get problems with the coverage, increasing each day : Google is desindexing a lot of URL with Server error (5xx).
It may comes from redirections : all the recently uncovered URL are redirected by the plugin Redirections.
Redirections plugin is still active, is there some settings to do in RM to fix this ? Is there a sort of conflict between the plug in and RM ? Should I deactivate the RM redirections?
Thanks 🙂