Yesterday I had an issue with my app and thought I'd post my solution here. On both the Galaxy Watch Active 2 and on the Galaxy Watch 3, Talk to Alexa wouldn't connect while connected to my phone. In other words the logo stayed white. My Active 2 worked on LTE though. Other apps also seem to have trouble connecting to the internet.
Turns out the problem was the "Samsung Accessory Service" on my phone. Things started to work after I force stopped the Samsung Accessory Service. I can imagine restarting my phone would've also helped.