your log is full of redis errors
[Thu May 02 17:18:49.831346 2024] [php:error] [pid 17148] [client 10.0.3.240:53240] PHP Fatal error: Uncaught OCP\\HintException: [0]: Memcache OC\\Memcache\\Redis not available for distributed cache (Is the matching PHP module installed and enabled?)\n\n thrown in /var/www/html/nextcloud/lib/private/Memcache/Factory.php on line 97
and it looks FUSE is not available
[Thu May 02 20:44:05.400937 2024] [core:notice] [pid 5618] AH00094: Command line: '/usr/sbin/apache2'
dlopen(): error loading libfuse.so.2
AppImages require FUSE to run.
I would
- start with resolving redis and FUSE issue
- continue with Collabora integration guide