MacOS user login not possible

Hello,

I use MacOS X High Sierra. In addition the current TeamViewer. This is started with the system.
If I now connect via TeamViewer (from a Windows PC), I get my 3 Benuzter displayed. If I now select a user with the mouse I can not enter the password of the user.
Sometimes I click on a user, just "blindly" enter the password and it works. But rarely works.
That worked wonderfully 1 month ago. But there are at least a MacOS X update and a TeamViewer update in between.
Do I have to adjust something in TeamViewer, so that works better.
I use TeamViewer 13 on both machines.

Does anyone have an idea why that may be?