When did you check this? They increased the FBA shipping costs around 4/17 so it may have some at the “old” rate and some at the new depending on the date range. I’m not saying there isn’t something funky but it might be as simple as that.
Last night. The SKU Economics was set for past 7 days. I checked the corresponding days on the transaction report. I ran the trans report for the past 30 days and could see the fee was $4.20 before the 16th, $4.35 after, never varying from those amounts during the time frames. The fba fee amount should not vary per order as the SKU Economics is showing. (Accessed through the SKU link on Manage Inventory).
No idea. That is strange. It should always be the same. Unless you’re looking at total fees and there was a price change to change the referral. Obvious that this isn’t the case here with the copy paste the OP did.