I don't know how but the issue has been solved.
I just reinstalled the mendix app twice and restored default http/https proxy settings.
Here's my solution for this issue:
LibGit2Sharp.LibGit2SharpException: failed to send request: The server name or server address could not be processed.
After some troubleshooting, I found that running the command below in a Command Prompt with administrator rights resolved the issue:
netsh.exe winhttp reset proxy
This fixed the problem for me, and I was able to work with my Git repository without any further issues.
Hope it helps everyone who comes across this issue as well!