Session cookies should expire approximately every 3 months, or when you manually log out of a website. If you find that yours are not working and are expiring too often, you might need to be careful!
Websites such as LinkedIn are always on the lookout for bots, so they keep a close eye on your activity. If your activity rate is too high, LinkedIn may see it as suspicious and log you out. This causes your session cookies to expire.
To prevent this, we recommend you decrease your activity rate. One way you can do this is by spreading your Phantoms' actions across several launches throughout the day (during work hours if possible). Setting up repeated launches will make this easy for you.
You should also keep in mind the rate limits for different websites to automating doing too much.