How to update a blueprint to recognize its parent class after it's moved into a plugin?

I moved some code out the main project and into a plugin. My code is working as expected, but the blueprints that extend from the c++ classes throw the error: “Blueprint x has missing or null parent class”. I tried re parenting the BP to the c++ class and it shows up as an option, but it doesn’t fix the problem. I’m able to create new BPs that derive from the plugin code and they work fine.

Having the same issue in 4.26. The parent class has the same name as before, but moved into a plugin and now the blueprints are all broken.