V44 both ends, latest Cubase 10.5:
I had never used the rehearse function prior to today. I switched it on to try to locate a point in the track with the performer and then I turned it off. From that point onwards there was no delay on the studio replay via the internet, so sync was out and the performer buffer showed empty. However on the LAN it worked fine. This remained the case through repair/remove/create, performer restarts, cubase restarts and even machine reboot. I could not restore VST connect functionality whatever I tried. Eventually through trial and error I re-engaged rehearse mode then disengaged it again and everything went back to normal.
Won’t be trying ‘rehearse’ again.