Is saying "I wish there were two episodes together" about a TV series that airs during the daytime in Ramadan and shows actors drinking an energy drink in it, considered mockery that exits the fold of Islam?

What you have mentioned is neither mockery nor disbelief. What you watch in terms of TV series diminishes the reward of fasting, and may even nullify it, but it does not break the fast. Therefore, you must fear Allah, stay away from obsessions, and maintain your fast.