Sonoff ZigbeeBridge only works after manual zbsend command

Dear members of the forum, I seem to have a little problem with some of my Sonoff ZBMini’s. Some work always from home assistant, but others (more distant ones) do only work if I have in the recent past activated them manually through the zigbee bridge’s console.
If I use the buttons on my home assistant dashboard, I see in the console that a zbsend was performed, but it returns a reachable:false error and the light stays of. Calling the same zigbee ID directly from the console ( zbsend {“device”:“0x9633”,“send”:{“power”:true}} ) works without a problem and once I do so I can use the home assistant dashboard buttons for a while to turn the light on/off.

Anyone who ever had the same problem and /or has an idea for a solution?

Thanks a lot!