@mastrmegatron
Which browser are you using?
Generally, if you have both "stay signed in" boxes checked (on the sign in page and in the user preferences) and are still having problems staying signed in, that would point to a problem with your browser cookies.
If you have set your browser to delete your cookies after each session, that might cause the behavior you describe. Similarly, if you using certain cleaner programs to delete your temporary internet files and cookies very often -- if that is the case there may be a way to put eBay on the "exempt list" as far as cookie erasure is concerned.
If you are not intentionally erasing your cookies, you might have an eBay cookie that is corrupt or blocked. Try deleting all your eBay-related cookies individually, and then go back and set that "stay signed in" box in the user preferences and hit "apply" after you sign in again.
If you still cannot stay signed in, try using another browser to see if that helps at all.
Signing in using your google or Facebook credentials is totally optional and should not affect your ability to stay signed in. I have neither of those linked to my account, and I have no problem staying signed in using Firefox, Edge or Opera browsers.
