Error al Abrir nextcloud tras funcionar correctamente

Hola

Tengo nextcloud instalado, ha estado funcionando bien, hasta que hace un par de dias cuando accedo a la url me aparece este mensaje:

"Internal Server Error

The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
More details can be found in the server log."

He tratado de instalarlo de nuevo, pero al lanzar el instalador me aparece este mismo mensaje.
Por lo que doy por hecho que el error no es de base de datos, ya que no me dá opcion de añadir la conexión y por otro lado tengo un wordpress funcionando en el mismo apache.

El equipo que uso es :
Description: Ubuntu 20.04.3 LTS
Release: 20.04
Codename: focal
PHP 7.4.3 (cli) (built: Aug 13 2021 05:39:12) ( NTS )
Server version: Apache/2.4.41 (Ubuntu)
Server built: 2021-09-28T22:28:10

En var/log/apache2/error.log me pone esto:

[Fri Oct 15 12:01:29.796761 2021] [php7:notice] [pid 4068] [client 127.0.0.1:54946] {“reqId”:“WKXKyJK2WOsU7JVbVOkt”,“level”:3,“time”:“2021-10-15T10:01:29+00:00”,“remoteAddr”:“127.0.0.1”,“user”:"–","app>
[Fri Oct 15 12:10:07.890953 2021] [mpm_prefork:notice] [pid 4060] AH00169: caught SIGTERM, shutting down
[Fri Oct 15 12:10:07.965689 2021] [mpm_prefork:notice] [pid 4286] AH00163: Apache/2.4.41 (Ubuntu) configured – resuming normal operations
[Fri Oct 15 12:10:07.965741 2021] [core:notice] [pid 4286] AH00094: Command line: ‘/usr/sbin/apache2’

En el apache access.log sale esto:

91.240.109.1 - - [18/Oct/2021:05:46:39 +0200] “GET / HTTP/1.1” 403 443 “-” “Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.0 Safari/537.36”
91.240.109.1 - - [18/Oct/2021:05:46:39 +0200] “GET / HTTP/1.1” 403 443 “-” “Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.0 Safari/537.36”
91.240.109.1 - - [18/Oct/2021:05:46:39 +0200] “GET /img/logo.png HTTP/1.1” 404 440 “-” “Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.0 Safari/537.36”
91.240.109.1 - - [18/Oct/2021:05:46:39 +0200] “GET /img/logo.png HTTP/1.1” 404 440 “-” “Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.0 Safari/537.36”
91.240.109.1 - - [18/Oct/2021:05:46:39 +0200] “GET /img/logo.jpg HTTP/1.1” 404 440 “-” “Mozilla/5.0 (X11; Linux i586; rv:31.0) Gecko/20100101 Firefox/31.0”
91.240.109.1 - - [18/Oct/2021:05:46:39 +0200] “GET /img/logo.jpg HTTP/1.1” 404 440 “-” “Mozilla/5.0 (X11; Linux i586; rv:31.0) Gecko/20100101 Firefox/31.0”
91.240.109.1 - - [18/Oct/2021:05:46:39 +0200] “GET /img/logo-1.jpg HTTP/1.1” 404 440 “-” “Mozilla/5.0 (compatible, MSIE 11, Windows NT 6.3; Trident/7.0; rv:11.0) like Gecko”
91.240.109.1 - - [18/Oct/2021:05:46:39 +0200] “GET /img/logo-1.jpg HTTP/1.1” 404 440 “-” “Mozilla/5.0 (compatible, MSIE 11, Windows NT 6.3; Trident/7.0; rv:11.0) like Gecko”

y el Nextcloud.log:

{“reqId”:“Co1SPGT4oJttMYgAWzKo”,“level”:2,“time”:“2021-10-05T11:21:27+00:00”,“remoteAddr”:“127.0.0.1”,“user”:"–",“app”:“no app in context”,“method”:“GET”,“url”:"/",“message”:“Host localhost was not connected to because it violates local access rules”,“userAgent”:“Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:92.0) Gecko/20100101 Firefox/92.0”,“version”:""}
{“reqId”:“Co1SPGT4oJttMYgAWzKo”,“level”:2,“time”:“2021-10-05T11:21:27+00:00”,“remoteAddr”:“127.0.0.1”,“user”:"–",“app”:“no app in context”,“method”:“GET”,“url”:"/",“message”:“Host localhost was not connected to because it violates local access rules”,“userAgent”:“Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:92.0) Gecko/20100101 Firefox/92.0”,“version”:""}
{“reqId”:“gavh1FagnK1MH734hW4C”,“level”:2,“time”:“2021-10-05T11:22:12+00:00”,“remoteAddr”:“127.0.0.1”,“user”:"–",“app”:“no app in context”,“method”:“POST”,“url”:"/index.php",“message”:“Host localhost was not connected to because it violates local access rules”,“userAgent”:“Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:92.0) Gecko/20100101 Firefox/92.0”,“version”:""}
{“reqId”:“gavh1FagnK1MH734hW4C”,“level”:2,“time”:“2021-10-05T11:22:12+00:00”,“remoteAddr”:“127.0.0.1”,“user”:"–",“app”:“no app in context”,“method”:“POST”,“url”:"/index.php",“message”:“Host localhost was not connected to because it violates local access rules”,“userAgent”:“Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:92.0) Gecko/20100101 Firefox/92.0”,“version”:""}

Alguien pordría echarme una mano,

Muchas gracias de antemano.