Also, note that there was an issue with the Wix Members collection in Dec 2019, so you might have been affected by this, for more info you can simply search the forum for previous posts about this.
Btw - if I do a search for a user that is already in the collection - no error. It is only when searching using an email address that doesn’t yet exist in the collection that the error gets thrown.
I looked at the links you provided and I’m doing everything according to those docs. The field name is correct, I’m passing an “options” that suppresses authentication and hooks, etc. Again, this worked fine until recently, and it won’t throw an error if the email address searched for already exists in the collection. It only throws the error if the value searched for doesn’t exist.
Yes, i checked and it seems when the email does not exist it throws an error. Probably a change to the way the collection responds (I think it is under going changes since December) . In any case its best you use the .catch(err) to process the function you wanted to when the email is not found for now.