oh no sorry to hear, It never happened yet thankfully. TG these Tapas episodes editable and you may be able to sneak it back in 
Not the exact thing but a couple episodes later, I ended up changing the relationship of a character to tighten the greater plot "now officially the protags' baby brother". (For context the protagonists are two brothers)
It felt like a challenging thing to do at the time -the lil kid, Neon went from being one of the protagonists' son, to the antagonists' son, to finally being the protagonists' little brother.
Having Neon be the little brother gives better focus on the two protagonists and their parents, and feels less cluttered without having to add unnecessary characters.
The other worry was that I had already showed their home in episode 3 with a 'shot of family photos' . But thanks to us being able to update episodes
I ended up sneaking a new photo of Neon into the family wall. It also worked well in the end because I was getting closer to the episode where Neon would be properly introduced.
And to not confuse old readers, I just made a special episode explaining the change that i made and also included snippets from previous episodes that updated as a result
Guess you were a lil lucky too as you said the cut off appeared as if supposed to b that way lol
Hopefully you find a way to indicate to your readers it was missing.
Maybe with a special episode telling them about the changes if you decide to?
Overall Tapas allowing us to edit our posted episodes = a rescue from horror stories lol