It was fast, it only took a few days for players to find another way to quickly get XP.
The creative mode had to be heavily limited because no matter how hard the developers tried to fix all the bugs and glitches, there were almost always players who somehow understood the mechanics of the game a bit too well.
It was exactly like that this time. For several days, there was a bug in the community that allowed you to gain unlimited XP. It didn’t require any knowledge or effort, it was enough to do one thing.
Fortnite Chapter 3 XP bug
Epic found out about it after several dozen hours and took quick steps to curtail leveling once and for all with the creative mode. Why? Just look at this way and speed of getting XP (video without audio):
What have the developers done? They just limited the ability to earn experience points in Creative Mode. In theory, this is temporary, but you can guess is that as soon as Epic fixes that particular glitch, the next one will appear.
At the end of the previous season, there was a whole lot of ways to level up, almost every day there was a more optimal path for completing tasks from NPCs, more errors in the creative mode, etc.