Chirpstack 4 - fail to get device lock on downlink to device

I’m in the process of setting up a new Chirpstack 4 instance. All seems to work fine except when sending a downlink command to my device.

in my journalctl I’m getting the following error

Mar 31 21:54:00 Chirpstack4 chirpstack[1391]: 2023-03-31T21:54:00.578222Z  INFO chirpstack::storage::device: Aquiring device lock dev_eui=691fc751b61263eb
Mar 31 21:54:00 Chirpstack4 chirpstack[1391]: 2023-03-31T21:54:00.583667Z  INFO chirpstack::storage::device_queue: Device queue-item updated id=7f2676e2-9953-408a-a4a7-e898199119e9 dev_eui=691fc751b61263eb
Mar 31 21:54:00 Chirpstack4 chirpstack[1391]: 2023-03-31T21:54:00.584647Z  INFO chirpstack::storage::downlink_frame: Downlink-frame saved downlink_id=1969184880
Mar 31 21:54:00 Chirpstack4 chirpstack[1391]: 2023-03-31T21:54:00.584740Z  INFO chirpstack::gateway::backend::mqtt: Sending downlink frame gateway_id=24e124fffef24129 topic=gateway/24e124fffef24129/command/down json=true
Mar 31 21:54:02 Chirpstack4 chirpstack[1391]: 2023-03-31T21:54:02.597274Z  INFO chirpstack::storage::device: Aquiring device lock dev_eui=691fc751b61263eb
Mar 31 21:54:02 Chirpstack4 chirpstack[1391]: 2023-03-31T21:54:02.597502Z ERROR chirpstack::downlink::scheduler: Schedule next queue-item for device failed error=Get device lock