git-credential-manager.exe path with whitespace character

I cannot fetch, pull or push since having installed the latest update 2.6.6.0 because whenever I do I get the error

C:/Users /Thomas: line1: syntax error near unexpected token `('

I was able to narrow down the search for the cause and found out that it is due to a whitespace character in my Windows user name, e.g. the location of the credential manager is

C:/Users/Thomas Flinkow/AppData/Local/Atlassian/SourceTree/git_extras/git-credential-manager.exe

and it seems to not work because of the whitespace character between "Thomas" and "Flinkow".

When I move the git-credential-manager.exe to a path that does not contain a whitespace character, everything works fine.

But I don't want to have to rely on an inconvenient workaround; instead of having to copy & paste every git command to the console, edit the path by hand and execute it then every time I want to fetch, push or pull I want to be able to simply press the buttons in the UI like it was possible before the update.