To turn off Polling
UI->Settings->Devices & Services
Find the Speed Test Integration
click on the 3-dots
click on System Options
You should see Enable polling for updates
Changing the Server-id not in the UI pull down list,
I’m not sure you can.
You could take a chance and change it n the the /config/.store/core.config_entries but be aware that these files are really not suppose to be changed, so I don’t recommend it.
Instead, I suggest going through this thread above and also this thread, where the speedtest-cli is used, and there you should be able to specify the server-id yourself. The speedtest-cli is essentially a binary executable that is run outside of HA and returns bandwidth/delay results. There are different ways that the speedtest-cli can be used with HA, and you’ll see in these threads a few ways to do it.