If you enter on Cfx.re Server List, select a server and try to connect it will not for RedM because instead FiveM will be opened:
This isn’t a bug, see this open issue
Thank you for sending additional information about this problem. About the terminology, if you like, let it not be a bug - I will change the topic title to “Protocol Handling Issue”.
Wait, what? This issue has existed for almost 3 years
I created a third party tool for this.
:3