We are running a 2016 Datacenter server under Azure. The server is primarily an RDS running Office Pro Plus and a couple of SQL backed applications.
Since Monday we've had problems with the user experience, with applications failing to clear down (Chrome was installed, would open once and close but then fail to open again - Chrome process remaining in background.)
The notifications for printing, new emails etc would appear but then fail to close afterwards. Left click on the start button would stop working and user experience was generally poor with noticeable lag on moving items on the screen. This sounds like a Shell type issue.
We have removed Chrome, disabled Skype for Business through GP, dialed down AV. We have run SFC /Scannow which found errors and fixed all except problems with Task Scheduler.lnk
Server is back up and we're waiting for it to happen again. Latest patch KB4489889 is applied, though this came out after the first problem.
What else might I have missed?