Sense features aren't working properly

[SunsetRunner]

Sleep tracker is off by hours. Heart monitor is nowhere near accurate. SpO2 simply will not work. It says it’s recording but doesn’t. No graph has ever appeared. It just tells me to download the clock-face and app, which I have done numerous times. The watch face constantly shows sleep to update. Step counter does not count floors climbed anywhere near accurately. 
I remove the watch to shower and while it is sitting on my bathroom counter, it is registering a heartbeat yet when I where the watch, half the time it doesn’t pick my heartbeat up. 
I bought this solely to monitor my heart during exercise. It is useless. While exercising, when it does pick up a heartbeat, the heartbeat it picks up is way off from the heartbeat that shows in the app on my phone, sometimes by as many as 20 bpm. 
Fitbit is junk. 
Is there a fix for this other than throw it in the garbage?

Moderator Edit: Clarified subject

[Gr4ndp4]

Hi, @SunsetRunner, welcome, it's a pity you are having problems with your "Sense", while you have not asked for any help I'll try and offer a way forward.

Sleep tracking requires 3 hours of uninterrupted sleep to function How do I track my sleep with my Fitbit device? offers advice and guidance.

Comments on accuracy can be found here - How accurate are Fitbit devices? including comments of HR. You will find that if you put your "Sense" face-up on a reflective surface you may get stray HR counts, I think this is caused by the sensor detecting LED flashes and attributing HR to them, solution place your "Sense" face down when you take it off. In some circumstances, a Fitbit HR monitor struggles to detect a pulse, particularly where the skin area under the sensor/LED array is tattooed or scarred. This is because the algorithm uses changes in the skin layer that is inked to detect a pulse. If you continue to experience problems in this area experiment by asking a family member or friend to wear the device, do they have the same problem?

How do I track blood oxygen saturation (SpO2) with my Fitbit device? will provide you with guidance and advice on the Sp02 readings.

"Floors" are detected by the reduction in air pressure measured by your "Sense" there's a comment on this in the link above on accuracy, you may also be interested in this third party article Fitbit floors climbed not accurate? Here's what to do. For my part, I do not pay much attention to this metric as "Floor" counts do not contribute to any of the other data streams.

I hope this is helpful, please post here again if progress escapes you.

Cheers