If you manually click "Log Out" on Facebook, the cookie you just copied will become instantly invalid. Simply close the tab instead.
To prevent your account from being locked or banned while using cookies: Get Cookie For Fplus Chrome Extension
Try to use a proxy if you are running multiple accounts. If Facebook sees five different accounts using the same cookie fingerprint on one IP, they may flag you. If you manually click "Log Out" on Facebook,
If you are using the FPlus Chrome Extension to automate your social media tasks, you know that a "Cookie" is the most important piece of the puzzle. Without a valid cookie, the extension cannot communicate with Facebook, which leads to login errors and failed tasks. the extension cannot communicate with Facebook