I've been using the Tuya app on iPhone for a couple of months, first with a Devola heater which broke down in a month so I sent it back, now with a Mylek.
I didn't realise until I got the Mylek that the UI for Tuya is driven by the device manufacturer not Tuya itself, so the UI for the Mylek is totally different to the Devola [which worked perfectly].
The Mylek shows as online to the app, but offline to the Scene feature in Tuya, seemingly no matter what I do.
The Mylek works fine if I'm addressing it directly from its own GUI.
The Mylek weekly timer (the  icon in the pic below), however, is an atrocious implementation, making me click one box per hour, for all 7 days, to set periods at which it should heat & to what temperature. It does actually work, though.
I decided instead to try the Scenes in Tuya itself. Set an on & off time, set a temperature [the rest I can figure out once I get this bit working].
On and working, from the Mylek GUI…
This communication works 2-way, if I change anything on the device's panel, it reflects here [so long as the child lock is off].
However, if I try to interact with the device in even the simplest way from the scheduler, it fails as 'offline'
The device is quite clearly not offline. As far as I'm aware I have no firewalling at all inside this network subnet, only to the outside world.
Any ideas as to where to look next? Or anyone aware of this as a 'known issue'?
Tuya & Mylek's online help structures are both pretty obtuse & mainly written in Chinglish.
Since first writing this I have discovered, by accident, how to make 'stripes' for on/off periods in Mylek's own interface rather than having to tap in every single hour - something which had eluded me for days. I'd still prefer to be able to setup these as events instead, as they would provide finer granularity.