This isn't about an error. I just wanted to talk about something. In the episode "The wedding crasher" it was stated to be Sam's parents' 20th wedding anniversary. If Sam's character page was right and was 22 in the episode then that means Sam's parents had her before they got married? That possibility just really surprises me.
The ages are all over the place in the show tbh. We can only guess how old all the characters are unless they have been stated (which for the most part they have not). I think the only main character whose age we know is Jerry lol.
I am skeptical of that being valid. First, they redesigned the character of Alex's father. Second, the lack of last names in the series casts doubt on whether the writers were serious about giving Alex a last name.