An invalid entry means it found the server but does not understand what the server stated back. Which means DNS has to be fine, else it would not have found the server that gave it the ability to make a request from the server in order to get back a response it did not understand.
As far as I know, the 53XX on the latest firmware that I linked is the only way for it to work with Office365, it is the firmware that resolved the issue where the printer did not have the ability to use SHA-2 for encryption, which would cause the error you are getting and 017-714.
Assuming you have logged into the email account the printer is using and did not get a "You must change the password now" message, and you did not enable 2-factor auth on the account (Both of those things cannot be understood by a printer and could cause your fault) then the only thing left is to do a Wireshark trace of the data on the LAN going between printer and Microsoft to see what the message is that it can't understand. If you can get that trace done, Xerox (assuming you have a maintenance agreement) should be able to figure out what is happening if you cannot.