Having exactly the same issue…
Trying to use CV out to OPLab, then OPLab midi out to Evolver.
CV A: pitch V/oct
Note 1: c2 - 1.000v
Note 2: c5 - 4.000v
CV B: Gate, v-trig, 5.0v
TUN, FIN, BND and SLD to 0 as well
CV LFOs/ENVs routed to nothing
Tracking fine, but it will randomly play the incorrect pitch after a note change. If I play it again, it’s fine forever 'til the note changes again.
No difference between using the sequencer, sequencing from trk1-4, playing slowly…
Same result routing the note out to either Evolver and OP-1.
And please don’t tell me to not play any key on the Evolver which could move the tracking around: there ain’t any keys on it 
@louvelle, did you manage to get it working?
Anyone? 