I suppose you are using nginx as proxy and apache as web server, try to change backend template PHP-FPM to no-php, save it and change it again to default or the php version you need to use and save again so the conf can be rebuilt.
Also, apache and nginx conf have some errors?
nginx -t
apache2ctl configtest
It’s been years since I used apache last time so I couldn’t help here too much.
apache shows: Could not reliably determine the server’s fully qualified domain name, using (myhestiacp).com. Set the ‘ServerName’ directive globally to suppress this message
Syntax OK