I was looking at AC035 upgrade to J , from lowest PE fare. Travel is 7.5 days away , thus just outside the upgrade window. At 8.5 days out, it was showing R9. So I booked the PE fare. At 7.5 Days out, it shows R2. The J seat map is unchanged [ I know this is not indicative, it’s just for info for you guys}.

What caused the "R" to drop by 7? Lat fare upgrades? AC simply adjusts it themselves?

I’m curious. Just trying to understand a little better.

Many thanks.