Why importing SVG files fails?

1/ I create an SVG file with Adobe Illustrator 2020 (vectorize, decompress, simplify, save).

2/ When I import the .SVG file (file > import or by drag and drop) I have the appearance of a black block (sometimes my file appears).

3/ I don’t understand my mistake. I’m looking to identify it, and how to properly import an SVG file without fail.

screenshot

To import the outlines, it might be easier to just copy paste them. Have you read: Importing from Illustrator | Glyphs