At this point, you have 2 options:
A) Keep trying Ford’s, I think there were cases where they pushed updates “by parts”, which seems to be your case. But for that to work, Ford needs to know what’s on the unit, that’s why I asked if the previous USB produced an XML file to send to Ford.
B) Use syn3updater from now on. You can follow this tutorial to the letter " Tutorial: 2020 North America 2.20 Map Installation (Stand-Alone without Reformat) with Updated NAV_Voice 06/21/2021 ", you can also use Syn3updater to generate the USB. It’s a lengthy process, so plan ahead to avoid interrupting it or having the engine turned off in the middle of the process. The tutorial is for NA maps, but general principle is the same for EU. It will take 1.5 / 2 hours since autoinstall.lst will have multiple sections (reboots).
Again, since your unit is MY20, keep MY20 protection active in Syn3updater since you cannot reformat the unit.
I’ve already answered this question, the answer is and will be the same.