Okay, so your complaint is that while you were having an issue with the DVR failing to record your games and refusing to allow you to set them up in the Guide (the essence of the glitch I described), you've already cancelled the series. But now while you are able to set up the recordings individually in the Guide, you still cannot create a new Series recording.
I would search your Manage Series Recordings list again and make sure that there are no other series marked either for any baseball games, or for that channel. Then I would go to that channel in the Guide, find the next game you are trying to record, make sure it is not marked to be recorded, and try the Record Series scheduling again.
I do not have that channel. But I just set up Series Recordings from the Guide and Search for MLB Baseball, and they both worked. Are you trying to say that this channel is no longer listing the Title as MLB Baseball in the Guide, but instead lists only the teams playing? That would be an issue for the channel and the Guide provider (who is expected to be replaced later on this year). Currently you cannot record programs based on content keywords (MLB Baseball). If it does not have the same title, it cannot be set up as a Series. In this case you can notify Verizon and they can notify their Guide provider. But you will have to continue to set up the recordings individually until the listings are changed.