Why does an empty collection appear every time we auto sync stock?

So we use inventory sync we have 7 collections all sync fine been OK for weeks but now every time we auto sync stock there appears a new collection empty of stock and no pic and we have to delete it manually so annoying 8 times a day. Can not work out why or how. We’ve double checked all over shopify and can’t find an answer. We have one that is correct called CBD vape with stock this one appears with CBD vapes and empty with one condition so we try to delete the condition so there is none but then can not exit so only option is to delete AGAIN