Nah! I don't honestly think that Spence Jr. would accept a 40% cut of the purse, he's been already vocal about it that he should have the bigger slice as he has more belt in the table and I think Crawford will happily get that 40% though just to make the fight happen because if this drags again then Crawford will be on the disadvantage.
There is no official news released that both parties are disagreeing with the cut. Maybe there are other things that it's not allowed to share in public for now about what's the current score, progress, and status of the negotiation of this fight as it might affect the pre-planned working deals. Just come to think of it, both boxers are desired to face each other and they are very vocal about their anticipated match.
Whether on what part they are still not agreeing, that will surely be settled as they progress.