Hi Ismael, I'm having a similar problem with Microsoft Edge Version 91.0.864.54 (Official build) (64-bit).
In one survey I have 6 select_one_from_file fields. 2 of them contain geopoint data, all of them are autocomplete.
One of the select_one_from_file fields (one that contains geopoint) dropdown is working fine. But all other 5 are not working - the field is there, the arrow is there but when I click on the field rectangle, the dropdown list doesnt appear. However, unlike ClaireC's example, my fields are not greyed out.
My non-external select_one fields that direct to my xlsform's choices tab work as normal.
I've tested your question with a test survey - with a select_one_from_file field, if I change the appearance to 'minimal compact' from autocomplete, the field seems to work as normal.