When trying to go to a group on the mobile website using the group URL copied from the desktop version of the website when logged on (Groups - Roblox), you will simply be redirected to Groups - Roblox
I’m using the Google Chrome app, and tried it on my phone’s default browser, but the latter uses the desktop version of the website.
It’s been happening for as long as the mobile version of the website has been around, I think.