Plug-ins virtually always need to be updated when InDesign has a major upgrade. I would suggest downgrading to CC 2015.4 until Sonar announces their upgrades. Most plug-in developers take between 1 and 8 weeks to have new versions out.

Normally that is what I would use conditional text for: https://creativepro.com/tag/conditional-text

However, while you can apply conditional text to the text inside the column, you cannot apply it to the column itself.

You should ask the printer if they will accept PDF/X-4. If they say yes, then that is definitely the best solution.

Scott: My guess is that you have a character style applied to the text inside the cell. That is the most common problem people have that results in a paragraph style not changing the formatting.

I also suggestion rebuilding your application preferences, and perhaps working in a new document. The table/cell/paragraph styles work fine, and don’t crash InDesign for us.

I agree with Kai on his suggestions!

Ah! I understand now… sorry. Here are some resources:
https://creativepro.com/laying-out-facing-pages-vertically.php
https://creativepro.com/two-tips-in-one-vertical-spreads-and-shared-layouts.php

No wait… those don’t focus on the main solution, which is to use the Rotate Spread feature in the Pages panel (which rotates the visual appearance of the spread)

Linda: Ah, sorry, I made a bad assumption (based on what people were saying previously in this thread). That’s a Mac feature. I wonder if the book panel is “disappearing” behind your InDesign application window. Like, if you move the whole InDesign window out of the way, is it hiding behind it.