When patching our 11.3 Enterprise Portal, we ask users to take their ArcGIS Pro licences offline for the duration, and then check them back in following a successful patch update.
On some rare occasions, a select few users report that either a), they're unable to check their licence back in, or b) they successfully check the licence in, but later on, they're informed that they cannot connect to the licence portal and will be logged out in 24 hours.

In the past we have resolved this issue by force deleting the Borrow key(s) from the registry:

But this is not a solution, simply a dirty workaround.
Has anyone else dealt with this sort of issue and can provide some kind of steer on a longer term fix? My guess is something to do with a corrupt user profile on the users azure VDI they access the software from.
David
..Maps with no limits..