.htaccess You don't have permission to access /index.php What could be the problem?

Question

Apache HTTP Server

shared hosting, tell me what could be the problem:
You don't have permission to access /index.php
If you specify the full path to this index.php in the link to the site, then everything is fine! There are such files, the rights are normal.
.htaccess file

Options All -ExecCGI -Indexes -Includes +FollowSymLinks
DirectoryIndex index.php index.shtml index.htm index.html
AddType text/xml xml
AddType text/xml xsl
AddDefaultCharset WINDOWS-1251
ErrorDocument 404 /404.html
RewriteEngine On
<Limit PUT DELETE>
order deny,allow
deny from all
</Limit>

At the same time, if you change the DirectoryIndex line, for example, to main.php (there are such files), then the inscription in the error also changes, i.e. this line is read correctly
. At the same time, if you go to some folder, and not in the root, then everything is fine too!
Before that, everything was fine, the hosting recently changed something in the server configuration and this moment broke, technical support is dumb.

Answer 1

ModSecurity™ Domain Manager was found in the control panel, disabling it helped. It seems to be very strange behavior.

Answer 2

Might not be right enough.