File uploading and attachment field only allows image and video files

Hi, I’ve been trying to troubleshoot this problem for days now. It happened after I updated the WP version of the website. I already tried downgrading but the issue is still happening.

If you try to choose a file to attach on the form, the doc files are all disabled, only images and videos can be selected.

I would greatly appreciate it if you could give me some ideas on how to fix this. Thank you.

The page I need help with: [log in to see the link]