When you changed the checkbox value on the field group editor page, it won’t change the value for each post/page in the database. That’s why the checkbox isn’t checked anymore because it still has the old value in the database, which is different from the new one.
To fix it, you need to perform SQL query to change the old value to the new one or resave each post/page that has the value set.
The conditional logic also depends on this value, so changing it will make the conditional logic broken. Kindly reset the rule again to fix it.
That being said, changing the options value is not encouraged as it can cause confusion in your system. If you can, please change the options label instead.
I hope this makes sense 🙂
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