Why does the div disappear after the form?

Question

PHP

Hello.
I'm shocked :D My block disappears after the form O_o
It goes like this:

<form>
inputs..
</form>

<div>
Этот DIV не выводится. Но если корректировать HTML файл в браузере и специально добавить его(div), то он добавится и будет выведен корректно.
</div>

I'm at a loss. This has never happened :D
I don't even know what else to provide. CSS is irrelevant because if you deliberately add a div with the same classes in the browser, then the div will display correctly as it should.
The problem appeared as soon as I put the site on the hosting.
I wrote a site on a local computer and when I decided to put it on hosting, this problem appeared (already on the hosting, everything is fine on the local computer with the same code).
The site uses Bootstrap.
Also written in PHP.
Help please :D

Answer 1

The solution was in PHP..
Due to require. When you enable a modal window, php pulls text from a third-party file on the server. But after moving from the local computer to the hosting, the file changed its location. Previously, I had: require('/text/text.html');
And now:
The whole problem was in the slash! Oh my God! This is terrible)
Thanks to everyone who helped)

Answer 2

The code breaks on line 140, look for an error on line 141?

Answer 3

It is logical that the problem is in some script