My facebook/messenger active status is missing even though I haven't turned the active status off. Whenever I became idle or offline, my status is missing and it doesn't the active xx ago. Any solution or explanation for this problem?
Are you using the FB Messenger app or through a browser? In either case this would have nothing to do with user settings that you set. This sounds like an actual bug in Messenger, especially if you're using the app version for Android or iOS. If you're using an app try uninstalling the last update (i.e., reverting to the previous version of the app) or even uninstalling and reinstalling the app if reverting doesn't do the trick.
If you're experiencing the problem in just the browser, I would suggest closing the browser entirely and logging on in a different browser, you can use the same browser so long as you've cleared ALL cookies and anything related to Facebook. Keep in mind though, that this could be a browser related issue so it's best to try it on a different browser(assuming you're using Explorer or Edge, try using Chrome or Firefox instead).
If none of these work you have my deepest condolences, but I hear MySpace is making a comeback, so chin up. 😜 Totally kidding.