I have an desktop running Ubuntu 22.10 that allows SSH connections and has a Plex server running on it. It generally runs fine except that it will occasionally refuse connections - SSH fails with Connection refused and so does a new Plex window. The network isn't down; any existing video stream doesn't stop and an open SSH shell will continue to work, I just can't add a new connection.
Are there settings I should be changing to increase inbound connections or ensure ports remain free?
Edit: journalctl doesn't return anything that looks like a smoking gun to me. This connection error occured multiple times yesterday, and this is the entire days logs from NetworkManager :
Mar 29 00:00:43 NetworkManager[864]: <info> [1680062443.3505] dhcp4 (enp1s0): state changed new lease, address=192.168.1.52
Mar 29 00:56:58 NetworkManager[864]: <info> [1680065818.2973] dhcp4 (enp1s0): state changed new lease, address=192.168.1.52
Mar 29 01:51:41 NetworkManager[864]: <info> [1680069101.3066] dhcp4 (enp1s0): state changed new lease, address=192.168.1.52
Mar 29 02:47:40 NetworkManager[864]: <info> [1680072460.2969] dhcp4 (enp1s0): state changed new lease, address=192.168.1.52
Mar 29 03:41:31 NetworkManager[864]: <info> [1680075691.3097] dhcp4 (enp1s0): state changed new lease, address=192.168.1.52
Mar 29 04:36:15 NetworkManager[864]: <info> [1680078975.3003] dhcp4 (enp1s0): state changed new lease, address=192.168.1.52
Mar 29 04:53:46 NetworkManager[864]: <info> [1680080026.3071] manager: NetworkManager state is now CONNECTED_SITE
Mar 29 04:53:46 NetworkManager[864]: <info> [1680080026.4636] manager: NetworkManager state is now CONNECTED_GLOBAL
Mar 29 05:31:29 NetworkManager[864]: <info> [1680082289.2930] dhcp4 (enp1s0): state changed new lease, address=192.168.1.52
Mar 29 06:24:14 NetworkManager[864]: <info> [1680085454.3034] dhcp4 (enp1s0): state changed new lease, address=192.168.1.52
Mar 29 07:19:56 NetworkManager[864]: <info> [1680088796.3271] dhcp4 (enp1s0): state changed new lease, address=192.168.1.52
Mar 29 08:04:06 NetworkManager[864]: <info> [1680091446.3069] manager: NetworkManager state is now CONNECTED_SITE
Mar 29 08:04:07 NetworkManager[864]: <info> [1680091447.5300] manager: NetworkManager state is now CONNECTED_GLOBAL
Mar 29 08:14:57 NetworkManager[864]: <info> [1680092097.3178] dhcp4 (enp1s0): state changed new lease, address=192.168.1.52
Mar 29 08:39:27 NetworkManager[864]: <info> [1680093567.3073] manager: NetworkManager state is now CONNECTED_SITE
Mar 29 08:39:27 NetworkManager[864]: <info> [1680093567.5565] manager: NetworkManager state is now CONNECTED_GLOBAL