My Virtualmin Pro licenses have been knocked off when I upgraded my servers to CentOS Stream 8 from CentOS 8, which I had to do as my CentOS 8 servers were both throwing errors and wouldn’t update as CentOS had been deprecated!
Probably too late now but I believe the suggested/supported upgrade path is CentOS8 → Alma/Rocky Linux (Centos 8 Stream has been repeatedly mentioned as not being supported by the developers here). I chose Centos 8 → Alma Linux 8.5 and am running Virtualmin Pro without issues (apart from the odd initial weird having to restart a stopped webmin service).
Having just done this again recently, I do realize this is MUCH easier said then done as it is now really difficult to download and install a copy of the now deprecated CentOS 8 so I think we all hold our collective breath that no server crashes between now and when the new production ready Virtualmin pro installer is released supporting Alma Linux.