When using arrayformulas, you will always have to delete the empty rows. Glide won’t seem them now that they are blank, but if you add new rows through the app, they will be placed at the bottom of the sheet.
Here’s a tutorial on it’s use:
And just my suggestion, unless you have a specific reason for performing the formula in the sheet…you could easily duplicate this same thing with a Relation and Lookup in the Glide data editor. It would be much faster as you wouldn’t have to wait for formulas to run in the sheet, which causes delays.