Why does Apple Watch Series 7 show long awake times that I am not aware of?

I use an Apple iPhone 14 Pro Max and Apple Watch Series 7 with GPS & Cellular for sleep tracking.

I also have an Inspire Sleep implant for severe OSA that runs every night.

I lost 50lbs. over the past year. My BMI is currently at 28.5.

I track my sleep every night. Most nights my Inspire device tells me that it was on for 8.3 hours. My Apple devices usually tell me that I have been sleeping 5-7+ hours. My good sleep hours are usually the first half to three quarters of my total sleep time.

Neither I nor my wife are aware of the lengthy awake times that are reported by my Apple devices.

It has been so long since I’ve actually felt “refreshed” that I don’t know how that feels anymore.

Is there a way to calibrate my Apple devices for more accurate and reporting sleep analysis?

Could the OEM magnet band that came with the watch be interfering with health monitoring?