exp_expiration cookie and exp_remember_me table

If the entry in the exp_remember_me table that matches the value of the exp_expiration cookie ( logged in user ) is deleted, does that mean the user will be auto logged out after 3 or 4 hours no matter what the cookie length of exp_sessionid is?

Background: We have an EE 2.9 site where users are being logged out after 3 or 4 hours even if remember me is checked. We found out that the entries in the exp_remember_me table were being deleted and the exp_expiration cookie pointed to nothing.