Very Occasionally Open Level Node Gets Stuck When Loading

I’ve done a saving system for my game, it save and load perfectly 99% of time, but occasionally when the game loads from main menu, it got stuck right at where it’s supposed to open the level.
I’ve attached the blueprint codes for the loading as below:

when it stuck, the loading screen comes up, but main menu music keeps playing and the screen is frozen from there, so I assume it’s where the “open level” node starts.

What could go wrong when something like this happens?

Still occasionally get stuck, I have no idea what caused it and it seems it happens rare but so randomly.