I’ve no experience concerning the effects of location changes.
Of course the country has to match on both apps.
Is it set to Hungary in Tuya mobile app?
I’ve checked the data center for Hungary, but that’s Central Europe as well.
About logs:
You can generate a diagnostic report via …More>Apps>Tuya Cloud and hit the sprocket (top-right).
Enter your username and copy the returned key.
Post a message in the official app topic, ask Jurgen if he can take a look at it for errors, and paste the key you just copied.