Can't select multiple files

Hello, I can't download more than one file at a time. When I try to select more than one file I'm not able to select with control or shift. Your instructions say use space bar or insert key and that doesn't work either. Any ideas? Thank you.
Version 5.19.2
Asus Laptop Windows 10

Can you post a screen record of what you are exactly doing?
Are you using Commander or Explorer interface?
If Commander, try switching to Explorer-style selection:
https://winscp.net/eng/docs/ui_pref_commander