Domain_not_verified when sending app submission updates even after verifying domain

Description
I am trying to submit an update to my App Submission. After verifying my domain (using uploaded HTML file) and filling in all the fields, I get a domain_not_verified error.

(this is my first post and I can’t attach images right now)

This is preventing me from submitting an update.

It’s strange because my first App Submission went through just fine. I tried using both Google Chrome and Safari, but am running into the same error on both.

I tried submitting again and it looks like the error resolved itself.