Buttons on index.html aren't clickable

[MrCheatEugene]

Buttons, that are not disabled, won't click!
Describe the bug

Button displays as button, but when I move my cursor over it, it won't change, and when I click on button - it doesn't do anything.
Onclick event works perfectly from console. Also, the same code for the buttons work on other pages.
To Reproduce
I am not sure how reproduce the bug, because it only happens randomly and stands even after refreshing the page, and in the NEW file it won't happen.
Expected behavior

Buttons.. will click?
Environment:

• OS: Windows 7, Ubuntu 18.04
• Browser: Chrome 96.0.4664.45 (Official build), (32 bit), Internet Explorer 11
• Build environment: VertrigoServ 2.58 32 bit with PHP 7; Apache 2 + FastCGI PHP 7.4

Suggestion(s) for fixing this issue
I don't know how to fix this.

Additional context
Everything WORKED before, but now it refuses to do so. It still works on other pages, but won't work on index.html
Also, will add site with issue: http://cip.stuff.mrcheat.ga/