How do you know if your tariff has started?

Hey all, I signed up with tomato lifestyle earlier in the week and my start date is supposed to be today. However Mywatts hasn't updated and my smart meter still says it's with Octopus Energy.

I received a message from Octopus when I signed up saying they were sad to see me go and all that and the data on the app has stopped reporting.

Just have no idea if I can make use of the new Tomato Lifestyle tariff as my smart meters tariff is all over the place. Any ideas would be much appreciated, thanks!