Stopped using Nexus years ago as ID, either at security (except to enter TTP priority security lines in Canada) and for ID at checkin/boarding. Too variable in knowing who might accept it and who might not. It’s just easier to use a DL or passport. It should be acceptable - it’s a REAL ID from a U.S. perspective too, and is therefore approved to use for TSA, etc. too many don’t know what it is - while it’s easier for me transborder, since it just sits in wallet, it became too much of a pain.
i do understand why it’s not if it is showing a past due expiry date, though. Though I think in the US, an expired DL can still be used for some time after for TSA (maybe 5 years?).