version 4.4 - slurs lost when "regroup rhythms"

It took me a while to figure out when the slurs disappeared, but I'm pretty sure it's as a result of asking the system to regroup rhythms. In 4/4 time I had slurred together the quarter notes on beats one and two, also three and four. Upon regrouping rhythms, it seemed the back half of the measure was unaffected but the slurs disappeared when they started on beat one. There were no rests within the affected measures, just four quarter notes.

Just an fyi. I manually repaired the slurs and haven't lost them again, as long as I stay away from regrouping rhythms :).