Got my new Unication last month, been about 8 months since I had one. I ran 6 different simulcast radio systems (Louisville MetroSafe, NKYRCS, Ohio MARCS, Indiana SAFE-T, Scott County KY CPSCS, Madison County, KY CPSCS) and one site from the University of Kentucky P25 radio system (all in one day, yes that's quite a lot of miles I traveled).
I put in all the talk groups by hand, never rebooted once on any systems. I have noted that my old G4 Pager, when importing Talkgroups, the pager would bug out and suddenly freeze on Scott County CPSCS, UKY, and Madison CPSCS.
It seems that importing causes issues. Most of the time I am programming off of an official list so the RadioReference imports are obsolete anyway. I also had the same experience with sites, never imported them on this pager, all by hand, works great.