Over the last 3 or 4 weeks when purchasing main cabin seats I have been surprised at checkin to find myself not on the upgrade list.

Messaged DL each time to get added and was told I had opted out (?).
Last week I was smart and verified a few days ahead of time and sure enough was in the system as an opt out.

Checked my profile and verified automatic u/g request to F/DL one/premium select (domestic only) and decline u/g to comfort +. (However as aDM may select a comfort + seat after booking as is my option.)

Experts, any idea what is going on??