KSZ8081RND: Linux works, Bootloader cannot write registers (cgudrian)

Hello! I am currently facing a strange problem with an KSZ8081RND connected to an i.MX6Solo on a custom 3rd party board (i.e. no schematic, sorry). While the PHY works perfectly on Linux (linux-imx 4.14.98) I have yet been unable to get it to work in the..