Upgrade from OSS 2.14.5 to 3.6.02 (process stops continously at "X minutes from last change")

Hi! we finally upgrade to latest versions:

Nexus 2 – OSS 2.14.18-01
Nexus 3 – OSS 3.23.0-03

The sinchronization is running.

We still see the synchronization stucks frequently showing this message (sometimes we see 4 minutes waiting in this state):

XXXXX processed, 0 minutes since last change, press “Continue” when ready

Is it normal?