http to https issue Ubuntu 16.04 - PHP 7.4-FPM

[Vegas10128]

Hello Vesta Users,

I have discovered an issue for first time users accessing website.
It appears the issue starts after enabling SSL and signing a certificate with lets-encrypt.

User navigates to domain.com
the browser will return with a "nulled" download file.

If i try to a file directly example:
domain.com/index.html

the server will download index.html

However, if i visit
https:// manually "https://domain.com"
the website will display!

I have not done any changes to vesta for quite some time, and vesta has never done this recently. My .htaccess file has also been configured to redirect http to https requests.

I have tried using the default php version, and different versions of php7.

I have tried the following
- modifying domain.com.apache2.conf, domain.com.nginx.conf, domian.com.apache2.ssl.conf, & domian.com.nginx.ssl.conf located in /home/admin/conf/web - directory.
- rebooting the server
- disable ssl on domain
- double checking .htaccess file

Has anyone experienced this before?

I have made fresh install on separate server with Ubuntu 18.04 and works fine.
What can i do to keep 16.04? as it is an important server.