Apple watch problems

On iPhone everything works fine! But watch app doesnt work properly! Please fix this! Its very annoying!
Apple watch crashes sometimes during workout and doesnt recover (cant be used anymore)!!!
Often, when i start the workout from the watch, it says i need to login at the iPhone app before i can continue! This sucks as i just want to interact with my watch and not the iPhone!
I have my iPhone connected to bluetooth earbuds und my watch to a heart rate sensor!

Lukas Witzani about Runtastic Running Tracker PRO, v7.1.7