RH2019 collaborate Version control - tfs

Hello, we use azure devops/TFS (version 2019.1) for our software development.

we connect to this server over https, being the norm today.

I just passed 2.5 hours trying to setup up a synch.

Wanting to take away the burden of local versioncontrol, manually check in and check out, and just healthy backup/restore procedures, and of course the automatic inclusion of my work in the project.

At a certain point, after choosing add project to connection 'tfs' , Robohelp did ask me my credentials (yessss). BUT...immediately RH (2019) pops up a messagebox:

Version control -TFS

Protocol "https:" not supported. expected "http:"

anyone knows how to solve this?

I'm not the only working on that tfs server. So changing the settings in tfs to the lesser secure http is not an option. I tried fooling RH (using http://tfs.domain.com:443/blabla) but this gave the same result.

best regards

Olivier