Blossom end rot can effect other plants, it isn't limited to tomatoes. My jalepenos have suffered from it and had very stunted growth, being the size of grapes. I would guess that is an issue for your pumpkins as well.
Hydrated lime works for the tomatoes, it would probably work for pumpkins, but of course check first.
2020-07-14 23:56:04 +0000 UTC
your pumpkin might not getting enough nutrients or it might be getting too much nitrogen. try to get a flowering or fruiting fertilizer with trace elements, also since your growing in containers try a weekly foliar fertilizer supplement like Peters Professional Fertilizer.