6x Pro Performance - Help Please.

Hi. 
I’ve had a Fenix 6x Pro 51mm since mid December. Had to exchange it after a week as it hardly recorded any sleep, heart rate was never displayed and cardio workouts weren’t recorded correctly. 
The new watch was working a lot better, up until 2 days ago. 
For the last 2 nights it hasn’t recorded any sleep, and I went for a run yesterday and the GPS map was wildly inaccurate. I’m not talking a few meters out, but 300m plus. It had my crossing main roads I hadn’t, running diagonally through buildings. 
I’m coming to the conclusion that for the money it’s a rip off! Lovely looking device and great features but my Apple Watch worked perfectly and for the money the 6x is a let down so far. 
Really hoping you can help in some way.