Site cannot be reached while downloading file

I’m Daffa, I’m proud to use CyberPanel for my web hosting panel, but it doesn’t work well, there are some problems.
I built a cloud storage website, before I shared it with my friends, I tested it first, did it work properly. While testing, I found a number of problems that I could not download some files and my website turned into this site unreachable, when I tried other files, it could be downloaded. I thought there was an error with the storage server but not everything worked properly. Is this a cyberpanel bug or what?
I hope you can help me.

This for example link