TeamViewer update doesn't work

On one of my machines (Windows 10 Pro) with TeamViewer 14.1.9025 none of 3 update methods work:

• auto-update: it just never happens, although it is activated)
• remote update: it says it does the update but when I reconnect it's still the old version, no error message shown anywhere
• manual update: it seems to update but after it restarted itself it's still the old version, no error message shown anywhere

The only way of getting this machine updated is downloading the latest TeamViewer installer and installing that over the old version.

This machine had this problem for a longer time already so it isn't something specifically with version 14.1.9025 - the same problem existed in all previous versions.

Any ideas what I can try? Thanks!