No upgrade offers when buying an itinerary via American Airlines?

I bought a one-way itinerary via Alaska & see a $675 upgrade offer.

Today, I bought the return leg separately (separate one-way itinerary) via Alaska & was seeing a $55 upgrade offer (in Manage Booking, after buying). But I canceled it almost immediately & bought the same flight ticket (codeshare) via American Airlines. Now I don't see an upgrade offer for this one-way itinerary when I go to Manage Booking (or something) on the Alaska Airlines website.

Is this normal? Can Alaska not accept payment for upgrades for codeshare flights marketed by American Airlines?

I could cancel the itinerary on American Airlines for a full refund & rebook it on Alaska but won't risk it because used both travel credit & credit card to book that American Airlines itinerary, and since they haven't refunded me yet for a similar itinerary I had canceled 2 days back (had paid with both travel credit & credit card. I should've received another travel credit & some funds should've gone back to the credit card since I canceled within 24 hours of booking), probably due to some technical issues at their end.