It’s a problem related to the channel version and the 64 bit client, it’s caused by byfron the new anticheat system roblox just dropped!
I have tried solving it myself but led to no response, But in my old post someone posted a fix, relating to a modeler that can change the channel from other ones to the “LIVE” channel!
Even though this fix was working for me, it only worked for a bit of time!