just received my new patterson multireel 3 tank, it takes 2 120 or 3 35mm reels. the is really hard to close, i have to push really hard on all sides (I can't just push on the center of the lid to close it, i have to push all around it to get it "locked in" part by part.
I don't have the particular model you do (and it is by Paterson, I hope) but I have used a fair number of these tanks in different sizes though the years. Some lids can get 'looser' and drip a bit with time, even when 'burped' to set the seal so perhaps Paterson is starting a bit snugger on the lids when new now.