Had the same issue, contacted host (WPE) and they said the following:
“We excluded /my-account from cache… and…We have a security measure on our platform which restricts the way scripts can interact with the login form. I deactivated that measure. I also added some additional cache exclusions to the live site based on what I was seeing in the access logs.”
That took care of it!
Thanx martine_cotton for the heads up.
