I have a list look up field in my form, when i edit the list item, sometime was no value retrieved from the list, but sometime can, i am sure about that there has a value stored in my list, any idea? Thanks.
Form when edit.
My List Record:
My list loop up setting
list lookups sometimes take some time to render completely. How long did you wait for the value of the lookup value? Not sure if you can see the traffic via F12->Network or something like fiddler. Your lookup fields configuration should be correct if it works in general.
If your latency to the nintex service is too high you can check with nintex where your tenant is hosted and have it switched if necessary. Afaik by default all nintex tenants are hosted in the US.