2gb to 4gb is around the average for most standard operation, so something unintended must be happening in the meantime. I was thinking the autosave could have been causing some ram usage, but it’s usually significantly less than that spike.
Is this only with widgets or other editor windows causing it as well? I’ve seen some weirdness (CPU not RAM usually) with a DPI issue (I’m not joking) with UMG but the fact it’s happening only in 5.1 this definitely seems to be something else.