Scag "slipping" during Drive

[Dogma]

48" Belt Driven Scag Walk Behind with intermittent pausing in the drive. Feels as though belt is slipping but tension seems good.
I will be moving along in drive and mower hesitates for a moment, then resumes normally. Any ideas?

 

[MarkSz]

Good Afternoon,

Did you ever find out what your problem was?
My Scag SW52v-15fs has the same problem but it is getting worse.