Didn't receive upgrade for character in PVZGW2 (PC)

I was playing Party Corn yesterday and reached Elite Level 5 and when I left my online game I lost all my xp progress for the character, I then levelled him back up to Elite Level 5 in the backyard and put the upgrade on him. When I loaded the game back up the following day he was Elite level 6 and the upgrade I earned the day before was locked again. I then upgraded him up to Super Elite Level 5 hoping that I would get both upgrades but I only got the Health upgrade from hitting Super Elite Level 5 meaning that I am unable to unlock the upgrade for hitting Elite Level 5.

I think the xp not saving after leaving an online lobby broke the game somehow, any fix for this problem would be greatly appreciated.

I've left screenshots showing that my Party Corn is Super Elite level 5 and the character upgrade being locked despite this.