For everyone wondering i found out the reason, when you enter a seekchase room or the nest (special room), the game sends a signal to your Roblox client to move the minecart by some certain parts (sending the path where you should move), and technically when you die the system resets, and sometimes the game fails to reload the session stuff correctly, causing it to stop sending minecart move signal. Edit: in the log as seen there is "no node" warning which comes from the minecart control script, indicating that something went wrong. (Also yall are saying the Main_Game.Updated is the reason, no its not, this script is only based for player current room detection & other stuff like sending signal to open doors, it does not have to do anything with minecart, and this error usually happens when player dies.)
Ah so after seing the errors it semmed that ur Ui actually was what broke. Witch is really weird. The ui is not supposed the break the game. And then also at the end. The game though u were doing the speed chase and tried to set your speed of minecart to 0 since the chase ended causing u to stop. But thats just what i think from reading the errors. Other people may think diffrent. And i might be wrong. I actually dont know
