I know this is late, but maybe you are still interested or someone is.
I’ve had the same issue and it took me a while. it is quite a simple fix in the end:
Upgrade to Android 10 before installing
There is a linked article* in the general instruction (that don’t mention this), and even the article is quite round about, though the info is in there. It really is just that one point, upgrade to android 10 before installing.
Then it is smooth sailing.
The fone (pun intended) is great for the price and so is e, soo many kudos to all the developers that make this magic work.