I did not sign up for it here but I chosed beta testing in Google play store. It took some hours for it to take effect but since then I'm running the app version 3.0.0 which got uploaded on June 11th, 2021.

I had a similar problem with my Sprite. In my case it was my fault because I used the wrong power supply: I used 24V DC instead of 24V AC.

It's interesting to see that the Sprite itself also works connecting it to 24V DC but the valves fail to do a proper job on DC (since my valves require AC. But according to Wikipedia there are also DC valves). It left me with a feeling of having a broken device until getting clarification from the support. 

It was hard to find a 24VAC power supply because it's very uncommon to use AC on low voltage devices, but now that I have a 24VAC everything works as expected. 

Oh, and if you have to buy a new power supply make sure it has at least 800mA (0.8A) if you have a Sprite. (Or look it up in the user manual if you have another device)

Hope this helps