Thank you for confirming functionality. Sometimes MPLS links won't run actual 1500 byte packets, but if it is just LAN (where TDP runs most of the time anyway), that rules that out.
If the VSM'ed copy works as a source, I would just use that and put it down to "weird issue with no longer supported version of 7DOT".
My thoughts include some form of missed volume corruption - but it's rare to begin with, and VSM should just copy the corruption over..
