I'm seeing mass of these in your logs
Oct 1 07:24:22 EmbyServer nginx: 2022/10/01 07:24:22 [error] 4438#4438: MEMSTORE:00: can't create shared message for channel /devices
Oct 1 07:24:23 EmbyServer nginx: 2022/10/01 07:24:23 [crit] 4438#4438: ngx_slab_alloc() failed: no memory
Oct 1 07:24:23 EmbyServer nginx: 2022/10/01 07:24:23 [error] 4438#4438: shpool alloc failed
Oct 1 07:24:23 EmbyServer nginx: 2022/10/01 07:24:23 [error] 4438#4438: nchan: Out of shared memory while allocating message of size 6038. Increase nchan_max_reserved_memory.
Oct 1 07:24:23 EmbyServer nginx: 2022/10/01 07:24:23 [error] 4438#4438: *3088717 nchan: error publishing message (HTTP status code 500), client: unix:, server: , request: "POST /pub/devices?buffer_length=1 HTTP/1.1", host: "localhost"