Can't submit entityform after ajax callback on select element
It would be useful to have the actual code you wrote to check if there are some errors.
If you check my relative question you can crossreference your code to check if there's something wrong (mine is currently working).
I'd suggest to:

apply the patch of this issue
if still not working do the same workaround I've used: check the $triggering_element to populate the select options only in the opportune moments of the form build.