Windows 10 1809 update disconnects support session

It looks like this is a Microsoft issue. (I've read that the update removes the built-in administrator account in some cases. They say they should have a fix later this month.)

Are you able to reconnect after rebooting?

Unfortunately, not without a trip into the office to reconnect a support session again. The support session does work with 1809 just fine once it's installed. It's just the installation of the update that causes the disconnect.

I would recommend installing a true Access Client,  or running them in tandem, in advance of the 1809 reboot. Then going back to a standard support session if the customer doesn't want your client residing permanently after the update reboot.