Wrist temp tracking stopped working

https://support.apple.com/en-us/102674

Here's what you need

• • An Apple Watch Series 8 or later, any model of Apple Watch Ultra, or Apple Watch SE 3.
  • Sleep must be set up with Track Sleep with Apple Watch enabled.
  • Sleep Focus must be enabled for at least 4 hours a night for about 5 nights.

Are you currently meeting all three of these criteria? (Obviously you meet the first one.)

If it is one at least 4 hours/night for more than 5 nights, it should show wrist temperate.

However, Apple cautions

"To get the best results, make sure your Apple Watch fits just right. If the fit is too loose, it can impact wrist temperature data."

So the wrist temperature detection depends on having the right fit.

What happened on Feb. 8? Did you do an update, replace a watch band, something else ?

Yes, I also track sleep but without Sleep Focus turned on. Is your Sleep Focus also turned on.