I’m unfortunately not too sure on this one, but one thing that may help - it sounds like the sub-workflow is not freeing up memory as expected. Can you make sure that your last node is a Set node that is returning very little or no data? It makes more of a difference than you might think, and there may be a memory issue with the Item Lists node that we didn’t expect to see.
In last node return 1 record , I don’t known why flow not free memory.
I try on 10,000 pre round and check round by Redis.
I monitor in first round use memory less than 2GB.
It’s use memory more in next round , in last round it’s use memory more than 12GB.