Note that uname can be a bit misleading because it shows the kernel version. It is possible (and in some cases necessary) to update the kernel and system sets separately, which means you can end up with uname saying 9.3 while the majority of the system is still 9.2. (Or the reverse - sets being 9.3 but kernel stuck on 9.2 for whatever reason.)
How to make sure the sets are updated as well? Check /etc/release. It's part of the base set, so you know at least the basic stuff got updated correctly. I don't know how to check for the rest of the sets, perhaps someone else can weigh in.
