I’m not sure you’ll get nice performance in local network with small appliances (consumer network hardware, mini PCs and rpi 4). I’ve never got sub-ms network disk access on 1Gbps switch and router. In the end I’ve done the opposite - I’ve added one k8s host with a lot of storage, and any storage services are deployed there. All the other k8s services rely on local SSDs.

Open a console with top/htop and check if it will be visible when the system halts.

From my experience it looks like out of memory situation and some process starts swapping like crazy, or a faulty hdd that tries to read some part of the disk over and over again without success.