Debugging help with GUIs?

I am suspecting that there is a relationship between the number of players in a game and how fast a GUI responds. For example, in a game I am currently working on (with another person), it always has at least 8-20 players online during daytime.

I have noticed then that the in-game Developer Console doesn't open until you die. If it does open, certain errors and print statements that should be showing up do not show up until the moment you die. Not only that, but an ImageLabel object doesn't load a texture until you die as well (press T, go to settings, & pick a decal to copy and paste from the ROBLOX Library if you want to see it on your own) . However, if I try to load the texture on a decal whose parent is a part in Workspace, it'll load almost instantly, even when I'm using the exact same method to obtain the texture.

On the other hand, I have noticed when I copy the exact same place to a different place slot where I can play alone, none of these GUI delaying problem occur. They will update fast when you prompt them to, not just when you die.

Could it possibly be that I have the ResetPlayerGuiOnSpawn property set to false, or is it that I set the players' characters to nil when they die?...or is it simply just player lag depending on number of players?

Could I get some thoughts on why this happens and how to potentially fix this?