I have a hosted feature layer that has some attributes with lists created and some without.
When using the editor widget, select a feature, edit one attribute, and then select and another attribute that has a list, I pick an item in the list and the value return to the previous value. When I pick it a second time it the appears correctly.
After initial testing, this only "appears" to happen on records that have not been previously edited. If the feature has been previously edited, then the list appears to behave as expected.
I will continue to investigate and post if more information becomes available.
Thanks,
JB