"File upload failed" on form

Hello,
I’m currently using the Premium plan.

I’ve created a form (questionnaire) feature, but I often encounter file upload failures on the website.

“File upload failed”

It doesn’t happen every time, but it occurs frequently enough that I can’t leave it as is.

I’d appreciate your help.

Have you tried fixing it anyhow?

Setting the Upload Restrictions and File Size Limits to 30.

and allow the all file format.

I feel like there’s nothing more I can do.