This is the heart of the problem at Bambu, and it is totally inexcusable. In a world awash in filament, there is zero excuse to be stocked out of anything. This speaks to their squeezing their supply chain to the point where there is no resilience, and shortages are a direct symptom of this abuse.
While one might forgive supply shortages from a Chinese company squeezed by low-margin products, Bambu has zero excuse given they charge a hefty 50-70% premium for what is often a subpar product, as has been posted recently across their filament catalog.
To answer your question, break out of the Bambu walled garden, and you will be forced into another world of wonders and better experiences. In my case, I wasn’t presented with that choice. Shortly after receiving my P1P, Bambu was stocked out of all major colors in both spool and refill. In fact, my first experience printing the skins for my P1P required me to buy PLA black from a third party. Given that I dreaded the notion of going off-script, I feared the worst, such as a bad warranty-voiding experience. But you know what? Bambu did me a favor. Once I learned that the Kool-Aid they were pouring was really swamp water, it opened up a whole new world of better service and quality at a 70% discount. Now, that may not seem like it’s worth it, but consider this value proposition: if for every 2 spools you purchased, you were shipped 5, would you take that offer?
I’ll admit the Amazon marketplace here in the US appears to be a far better bargain than in the EU, but I believe there are similar bargains to be had in the EU. I mean, hell, Prusa products would have been at the top on my list if they had distribution in the US back when I first purchased my P1P and you folks in Deutschland have them at your doorstep, why not give them a try.
BTW: I just checked Amazon.de for filament prices and I take back what I said about US being more bargain-oriented. There are a whole batch of quality choices, from, ESun, Sunlu, Overture and ERYONE and whole host of filament companies that passed my own test and they are available from 10-14€ which is directly competitive with the $11-15 costs we see for the same product given exchange rates of today August 1, 2024. So there is no excuse not to branch out.