I can't find yet which commit affects it because v2025.10-rc1 has 1025 commits from 2025.07.
RK3588 boards should be usable without the additional patches that LE is using (which are mostly for 3576 support) so clone u-boot sources and start a git bisect to track success/failure, but use the githashes (and no patches) in the LE buildsystem. No matter how large the number of commits difference between the start points is, bisect will find the breaking commit within 8-10 moves, and if the rest of the LE image is static this is probably no more than an hour of effort. NB: I normally edit scripts/uboot_helper so I don't waste time building images for hardware that I won't be testing with.