I solved this issue by brute force.
I have currently two Rock64 SBCs, one with an SD card (and which I used for INDI) and one with an eMMC memory module, which I was in the process of upgrading. I reformated the eMMC Rock64 and installed everything from scratch. Now it works. The other SBC (with SD card) will get the same treatment, so I have a back up.
I also have a Rock64PRO incoming (has just cleared customs) with an eMMC module, which I was planning to use this for other projects, but I may just make it my main astronomy controller.