The reason you got this problem in the first place is that you regularly overfill your gas tank. When you fill the tank beyond the first click of the pump handle, you reduce the headroom in the gas tank for expansion of the gas.
FYI, I had this happen to me, even though I knew not to overfill, but I though rounding up to the next dollar would be OK, but it wasn't.
The gas enters the tank at ground temperature and will expand if the air temp is higher. If the headspace is not great enough, excess vapors and even raw gas gets pushed into the canister. At some point, right after filling the gas tank, the canister got saturated and tripped the light.
After a couple of days, the canister dried out enough to let the light go out. If you stop overfilling the gas tank, stop on the first click, you should not see this code again.