After fresh install NextCloud home page does not load by default index.php

Hi,

I hope you can help me with this.

Fresh installation of HestiaCP (admin UI on hcp.example.com under admin user). Created a user and added a few web domains under this user:

On firstsubdomain.example.com installed a static web site (simply created an FTP user and uploaded the web site). Main page is index.html
On secondsubdomain.example.com I successfully installed NextCloud however, the minute I click on the arrow icon (the one which appears as I move the cursor on the web domain to open its URL), instead of opening the nextcloud home page at https://secondsubdomain.example.com/index.php/login it opens the Work In Progress page:

By the way, if I load the full URL of NextCloud https://secondsubdomain.example.com/index.php/login, it works fine.
I have another environment (it’s a testing environment configured exactly the way the main one in Production is configured) and this issue does not occur there.

I checked the .htaccess file under the public_html folder of the affected web domain and the directive below is there:

DirectoryIndex index.php index.html

This is a mistery.

On another note I have PHP-7.4 and PHP-8.0 enabled and NextCloud is running on PHP-8.0.

Thanks in advance.

Regards.

~Ivano