In this case it looks to me that openHAB is somehow configured to send the power ON to all switches ( the items all switch to ON), but only the mqtt messages get through.
Why only the “predicted” message is logged might be a further indication, however I can’t tell the reason for that.
Hi helipus, how did you flash this device? I could not find any information on the flashing process for this device via Google.
Did you just soldered wires to TX and RX and flashed a basic Tasmota firmware to it? And then used the template from Gosund P1 Power Monitoring Power Strip (P1) Configuration for Tasmota to configure the Tasmota to the device?
Thanks!
Hi Frank,
You don’t need to solder. I flashed all my Tuya chip products which before ran in Smart Life with the same process via the software Tuya converter which ran under a unix installation with an wifi adapter.
You can run it either on your raspi or you can use a Live Ubuntu or Kali image with your can boot from an USB Stick on your windows computer. I used the Live USB Stick.
Here is the general Idea describe how it works:
Here is the software and the step-by-step manual:
Here some other non official guides:
I recommend you most the github documentation.
After your are finished flashing Tasmoto on the device, do an updated and then use the provided template from Gosund P1 Power Monitoring Power Strip (P1) Configuration for Tasmota
Thank you for this detailed list! 
The process using a Linux live image looks very promising for me.
I did create my Live Image with a persitence storage on my USB stick via the programm called Rufus:
https://rufus.ie/de_DE.html
In case it helps, we also have a tutorial here in the openHAB community.
I ran Tuya-convert on my RPi using a spare SD card with a fresh Raspbian install. Later on, I put that image on a second RPi to run Pi-Hole and CUPS, so now I have it available any time I need to flash a new Tuya device.