But the frum inflation has been significant outpacing national inflation, it can’t just be Hashgacha and transportation, though those might definitely be contributing factors.
Purely hypothesizing.... I know that one of the big meat producers had a major packaging issue. It's possible that they aren't big enough to negotiate their way through shortages, and therefore end up paying a premium and passing it on to the end user. This can be applied to any Kosher sector.
Further hypothesizing: there are serious supply issues for parts. When a major player has a machine or 2 down, a) it's a smaller percentage of their overall operation that is affected, and b) they can buy their way to the front of the line.
Kosher producers are relatively small fish in the food world, and are more likely to feel greater adverse effects from issues which others can absorb more easily.