(TL;DR at bottom) Ranorex does not actually do any "source control" itself and for TFVS specifically, it is all handled by Team Explorer in the background. Ranorex uses a tool provided by Microsoft to directly communicate to Team Explorer (MSSCCI). Ranorex Studio is essentially forwarding commands to Team Explorer via MSSCCI to help streamline the process and prevent you from having to open Team Explorer to manage your source control.
Since Ranorex is limited to the capabilities of this old MSSCCI tool that Microsoft does not update (to promote the use of their Team Explorer client), I personally recommend not using the TFVS integration in Ranorex Studio and simply using Team Explorer directly. You will gain many more options and features directly related to TFVS in a client designed purely to manage your TFVS repository.
The only downsides: having to have another window open on your machine (Team Explorer), and not being able to directly manage your source control from Ranorex Studio directly. Microsoft does offer a standalone version of Team Explorer
here if you do not wish to install the entire Visual Studio suite.
Now knowing all of the above information, this is very likely not an issue with Ranorex, but with the MSSCCI tool or your TFVS repository settings/configuration which are both out of Ranorex's control. If this is a MSSCCI issue, using Team Explorer directly should resolve this issue. If the issue still occurs when using Team Explorer directly, the issue is with your TFVS repository settings/configuration.
TL;DR: Try using
Team Explorer directly instead of the integration with Ranorex Studio.
I hope this helps!