We struggled w/ our fridge sense day one. Added a fan unit on the back(exterior) side. That helped some. We have now added a fin fan on the interior. Ended up going w/ the one in the link below (~$50). It’s not fancy but during a recent 3 week trip, between the 2 fans we saw a 10-15F drop in the max temp swing plus No spoiled food and no frost build up in the fridge itself. We did get frost in the freezer but it appeared to be much less than previous trips.
FYI - we had been using 2 battery powered fans inside before we had the fin fan installed.
Very happy w/ the results.