openHAB cloud connected but notifications do not work

I have used the openHAB cloud for years now and have not changed my configuration for several months. I am running OH 3.4.2.

openHAB cloud is online, I can see my sitemap remotely and control everything.
My problem is that notifications are not transferred to the cloud since Feb 19. I have tried several ways of posting updates (sendLogNotification, sendNotification, sendBroadcastNotification) to the cloud, none of them work.

The log looks like this:

2023-03-02 16:38:14.324 [DEBUG] [] - sending log notification 'SD_Jis1_Waschmaschine_Status.state'
2023-03-02 16:38:14.326 [DEBUG] [o.openhabcloud.internal.CloudService] - Sending log message 'SD_Jis1_Waschmaschine_Status.state'
2023-03-02 16:38:14.329 [DEBUG] [] - sending broadcast notification '12' to all users
2023-03-02 16:38:14.333 [DEBUG] [o.openhabcloud.internal.CloudService] - Sending broadcast message '12' to all users
2023-03-02 16:38:14.340 [ERROR] [internal.handler.ScriptActionHandler] - Script execution of rule with UID 'waschmaschine-2' failed: An error occurred during the script execution: Could not invoke method:,java.lang.String) on instance: null in waschmaschine
2023-03-02 16:38:22.184 [DEBUG] [io.openhabcloud.internal.CloudClient] - Socket.IO ping
2023-03-02 16:38:22.224 [DEBUG] [io.openhabcloud.internal.CloudClient] - Socket.IO pong: 39 ms
2023-03-02 16:38:47.227 [DEBUG] [io.openhabcloud.internal.CloudClient] - Socket.IO ping
2023-03-02 16:38:47.266 [DEBUG] [io.openhabcloud.internal.CloudClient] - Socket.IO pong: 39 ms