Google says that the Pixel 2/2 XL MMS issues have been fixed, but users are still complaining
In the Google Product Forums for the Pixel 2 XL, a Google employee named Pankaj Kanwar (who was representing the Pixel team) put up a post that said, "Thanks everyone for reporting this issue. It should now be resolved. Please let us know if you continue to encounter the problem." Many of those who responded to Kanwar's comment said that they are still experiencing the same inability to receive MMS messages. A few can't even send such a message on their Pixel 2 or Pixel 2 XL.
Based on the posts that we read, it appears that this issue is affecting those who are customers of AT&T or the latter's pre-paid Cricket service (which uses the AT&T network). There is a workaround for those who haven't been helped by Google's fix. This involves disabling the "Enhanced 4G LTE Mode" by going to Settings > Network & Internet > Mobile network > Advanced.
Even if the workaround does allow Pixel 2 and Pixel 2 XL users to see their MMS messages, it shouldn't stop them from complaining to their carrier and to Google about having to disable the Enhanced 4G LTE Mode.
source: GoogleProductForum via AndroidPolice