My guess is that partnering negotiations are still ongoing for some reason. These haven’t been updated recently, but here is the 2025 H1 update on the situation at that time. At that stage, the only market for which an agreement had already been signed was Germany.
edit: I dug a bit more into the Astellas report. I found this small print regarding Xtandi.
Global sales expected to be the similar level YoY (excl. Fx impact), with growth of ex-US markets mitigating the negative impact of U.S. Medicare Part D redesign
So, the Medicare Part D redesign affects the sales price of Xtandi in the U.S. This likely also slows down the agreement on sales and distribution terms for nanoenzalutamide in the U.S. Milestone payments are probably tied to sales targets, but if there is still uncertainty regarding the sales price, the agreement on those milestones could be delayed.