My lamp had worked about a week or two and after this period it forgot how to connect and switched to offline.
I can connect it again via another phone. But I would not like to do this every week.
I think the lamp wants to connect to the server that my home provider blocks in DNS. When the lamp connects via hotspot on the phone it saves ip-address in the cache and then connects to your servers by ip-address, not by name. When cache becames invalid the lamp again asks DNS and again can’t connect.
I can’t tune DNS server on my router. This option is disabled by provider.
If you tell me server names I can ask provider why these addresses are blocked.
Or maybe there is possibility to tune the lamp to connect to servers by ip-addresses instead of names? Or something else