Hi, @mattmar it's a issue i also had on my MXQ pro 4K you could try this method https://github.com/jhswartz/rk3229 from Justin Swartz, i have made a more automatized version to build and flash on a sd card to run, it's ubuntu withouth ui just command line you could install xfce from it, also while trying to find what makes this work and not armbian i found the problem it is on cpufreq_dt driver disabling it on kernel confguration is what make it work at least on my device but i don't know how to solve it, for now it's possible to boot ubuntu for arm but it's not even near as good as armbian.
EduSSantoz got a reaction from Joaquin Javate in problems with multiboot and board rk3229-mxq-8723 v1.0 MXQ pro 4k 5g