Dynamic Groups Not Updating

Summary

Our dynamic groups have stopped updating and we haven't been successful at manually triggering

Content

We seem to have the return of an issue that plagued us previously.  Our dynamic groups seem to have stopped auto updating late last week.  I know a number of us have had this issue on and off before. But ours had been pretty reliable for 9+ months. Previously we could at least manually force it to resync by going to the group, previewing the criteria (without changing) then clicking save. That isn't working this time.  It shows a new start update timestamp but never completes (we've been waiting 2.5 days).  We have an SR open and we think Oracle