SourceTree W10 not refreshing GUI on any action

New install on W10, 3.3.6 I am unable to use Sourcetree as the interface does not refresh after any changes. For example, staging a file does briefly pop-up the log window, but nothing changes in the view. I then need to press F5 the file to move to the Staged files window.

This behaviour is the same for pretty much all actions as far as I can tell - restarting the app does sometimes not show any difference either.

It also doesn't automatically show changes made by other git applications to a repo. 

This was working fine in W7.

I have tired changing the "auto-refresh" settings and there is no change in behaviour.

Using procmon I can see Sourcetree.exe is opening the repo folder presumably to scan for changes.