Multiple devices connected to Tuya

Hi,
after days spending with the setup of my house for one device I found a way to synchronize other devices to HR.
Setup:
iPad, iPhone1, iPhone2, PC

HR
devices:
Tuya only scenes!, Smartthings TV

It is always one of the mentioned devices able to send commands to Tuya.
Does anybody know why?
BTW, on all of the mentined devices I have TuyaSmart installed and it is up and running…