TobyMac

This can be done with an ugly database hack, but we need 100% certainty of the transition year, because there is no undo button. Giving a hard date is difficult, because it often occurs that one color is sooner swapped than another, depending on stock and usages in sets,

@Nathan can you explain this? I don't have a brockset account, so I never worked with the link stuff.

Looks like 3436: https://rebrickable.com/parts/3436/vehicle-tipper-end-sloped/

If you have them linked: yes

Should have been my first guess. I had the same issue...

All 3 sets are under 50 parts. I believe the standard is put on >50 in the search (the difference between 0 and 50 is small on the scale). Otherwise, I'm at a loss here.

I assume you don't have any sets marked as 'Built'?

These are the settings I use

I do get them:

I have a test-account. Can you export your setlist and post it here? Then I'll import it and test them.

If all setting in the calculation are correct, the only other thing I can think of, is that the set list the missing sets are in, is not active for the calculation. You can check under My LEGO -» My Set Lists

Might be the standard year range?

There are a lot of build options. You can change them in the screen where you calculate the buildable sets.

Here is the list for 8 Studs: https://rebrickable.com/users/TobyMac/lists/52785/

Looks good to me