why am I unable to update firmware on my AirPods Max?

Apple Support did not resolve my firmware update problem.

Their response and remedy is disappointing.

I have two Apple AirPods Max with the same defect, that was not cause by a modification or damage after we opened our packaging. These devices were gifts, and were received new, in the original packaging. If there is a unrepairable problem, it must have occurred before point of sale.

I have many other Apple products, but this level of support will cause me pause in the future.

You need to be patient and follow Apple's advice in About firmware updates for AirPods - Apple Support. Be aware the update might not happen immediately, it could be several hours or even another attempt on a different day. In general it is "nice to have the latest version" but it is not critical and your AirPods will still work.

If you are having problems with the performance of your AirPods, or it is vital that their software is updated, please Contact Apple Support as noted in the support document, or arrange to visit the Genius Bar at a convenient Apple Store.

Thanks for the followup detail. That is almost unbelievable bad luck, I wish you success trying to get the refund.