We have 20+ Xg and XGS's deployed. We started pushing out the mentioned version updating from 18.5.3 MR-3 Build 408. The first 2 devices we updated had all kinds of VPN issues. Users could connect but the connection speed was garbage (less than 1mbps down). Was on the phone with support for over an hour. Finally they came back and said "after conferring with his colleagues there are issues with Version 19 we recommend you rollback". We did this and all the VPN issues were resolved.
FRUSTRATING to say the least. I have reached out to our Sophos Rep regarding this and updates moving forward but so far "Crickets"