Send Downlink At AS923-2

Hi everyone,
I’m having an issue with sending downlink messages from ChirpStack to my WisBlock Kit 4 when using the AS923-2 frequency plan.
Previously, when I was using AS923-1, everything worked fine — I could send downlinks without any problems. After switching to AS923-2, uplinks are still received normally, but downlinks never seem to be delivered to the device.
Thanks in advance for your help!