No one here, or anywhere, can tell you the "why" of your problems, but we may be able to help you discover the cause or fix the result.

Do you have the Track Changes button in your Status Bar?
I'm unsure I understand your question about the footnotes. Could you give more details?

Do these problems happen if you start Word in safe mode? (this is a diagnostic test)
Open Office apps in safe mode on a Windows PC - Microsoft Office

By the way, you should change your profile to indicate your version and operating system.
To get the best answers here, please ask a single question per post. Your questions are really not about why word is misbehaving but rather why Track Changes is turning off and why your footnotes are not working as expected.