I have a weird problem. I've loaded in QGIS a point shapefile and a CSV table. Then I performed a join between the 2 layers and all works fine.

But then the joined columns (made of integers or real numbers, it doesn't matter) are not recognized as numbers but as strings.

Even if I save the shapefile (original + join fields) and I reload it in QGIS the columns are always seen as strings.

BTW: I saved the CSV as a DBF table but same behavior.

Am I missing something?