DNX5160BTS won't read unlocked Garmin maps.

[pimz3001]

Hi, my 2014 DNX4250DAB died last week and I scored a second hand 2016 DNX5160BTS. Trying to update the Garmin map with unlocked 2022.10 ones I also used (succesfully) on the 4250 and a Zumo 660, but no luck on the 5160 yet.

- Just as on the DNX4250 I put gmapsupp.img in sdcard garmin dir.
- Device shows 'loading maps', but map is not shown.
- When I do the same with a locked map, it says that it can't unlock it, so it is recognized.
- When I put OSM or other free or unlocked maps, they are shown and they work.
- I opened the DNX5160 and there's no internal sdcard like in the DNX4250 (at least not on the daughterboard).

Any ideas where to go from here?
Could it be that the device checks for Unlocked Garmin maps and if yes, how? I thoughed it could help to changes names and Family ID and tried tools like Gmaptool, mapsettoolkit and Javawa DeviceManger, but no luck yet. I don't get anything changed other the the mapsetname. But that can also be my lack of knowledge....

If all fails I'm willing to buy the update. On this forum I red that I possibly can reuse the (update-)sd card in the future and only change the img's with unlocked ones. Did anyone got that working?

Side note:
I think the DNX5160BTS accepts only 2 maps on the SDcard: gmapsupp.img and gmapsup1.img. It doesn't show gmapsup2.img.