Welcome! This forum has a treasure trove of great info – Scouters helping Scouters! Just a heads up, though - all content, information, and opinions shared on this forum are those of the author, not the BSA.
The Reading Merit Badge still has the 2004 requirements listed in Scoutbook, not the requirements that were updated as of Jan 1, 2020. We have scouts working on this merit badge and need to be able to record completion of the current requirements.
Were the Scouts already working on the Reading merit badge prior to the new requirements coming out? If so, they have the option to continue using the old (2004) requirements or they can choose to switch to the new (2020) requirements (Guide to Advancement section 7.0.4.3 What to Do When Requirements Change).
OK, it sounds like someone selected the 2004 version year instead of 2020.
If any requirements are marked as completed in Scoutbook, then the toggle to select the version year will be hidden. After the requirement completion dates are removed in Scoutbook, the toggle will reappear.