I actually got them to stop in my game, with some modifications. I had the same problem. Cook, finish, cook again, finish again, cook, eat. What I did was hijack a buff in the game (no idea what it's for but it's underused) called "recently prepared food". Altered the looting so it was always received. Then went in to each autonomous cooking option on the fridge, and added it to the loot list. Then I added the buff under blacklisted items, so if a sim has it, they can't do that interaction. So what happens for example is, they autonomously choose to cook a single meal, immediately get the recently prepared food buff before they even finish, so when they are done cooking, they can't do it again for an hour. Instead they now grab the food they just made.
I think the problem is, something in the game has changed and they are making their decision on what to do next BEFORE they are done cooking. Maybe autonomy speed was tweaked? Because if you watch closely, they decide to cook again (or grab a snack) too early while they are still cooking and the cooking they are doing is still in the queue. And they choose to cook because they are still hungry and technically there is still no food to choose to eat because they haven't finished making it yet. What may be eventually interrupting the chain is eventually having to move a bit more before putting the food down (because of all the filled counter space), and maybe it gives them time to think. Or it's a meal type that they manage to finish making quicker.
Just a side note, a bunch of my sims (who aren't from Sulani) have a buff called "buff_islandculture_extrafood_completeobjective". No idea what it is, but it sounds like the sort of thing that could cause sims to cook.
