I disagree thepogg. I don't know specifically about Betsson, but most Microgaming and other many programs subtract "progressive contributions" from your revenue before commission is calculated. When a player wins a progressive jackpot, the casino pays the player nothing apart from the previously accumulated pool which is commonly shared across multiple casinos and paid for by the players and the affiliates. It costs the casino nothing apart from possibly some kind of fee they pay to participate if it is pooled. If it is not pooled and they have their own jackpots then they are fronting up the initial seed money then the rest is paid by players and affiliates. Ask an affiliate manager and they will all tell you that they love it when a player wins a pooled progressive at their casino as there is a chance that the player will play some of it back. This is pure profit for the casino as it transfers money from players to the casino (sometimes from players at other casinos obviously). This is also good for an affiliate if you referred the winner.
The game in question was Alice's Wonderland by Ash Gaming. It is available at many different casinos but I don't know if the jackpot is shared across them all.
Lets look at Affiliate Lounge's terms:
https://www.affiliatelounge.com/terms-of-use/
Bingo. Affiliate Lounge is already charging the affiliate for the player's contributions to the jackpot pool. Any players that were not referred by affiliates were paying it as they played. The winnings should not be subtracted from his commission. How many times do they expect to be paid for the same thing?