Paintings missing - or am I missing something...?

Hello,

before potentially wrongfully filing a bug-report I thought I'd rather ask my question here first:

Up to this point my understanding was that you're able to buy certain painting from the Joyous Painter in idleshire once you've completed the vista for that painting - at least for the ARR ones, I know that you need to complete the full sightseeing log for HW and SB to get any painting from those.
However the paintings that I'm having trouble to obtain are infact ARR ones - specifically "Gullperch Tower" and "Navigator". I have yet to complete the full ARR-sightseeing log, but I did manage to unlock both thise vistas.
So... why isnt the Painter offering them? Hes got lots of other paintings, even those from vistas that come after Gullperch and Navigator... so am I missing something with those two? Are there actually more requirements to paintings than just having the vista unlocked?

Like most things in this game, paintings are tied to achievements. You need to complete a full set (example 1-20) and get the associated achievement before you can buy any of those paintings from the Joyous Painter.

I have completed 1-20 and I am able to buy paintings that are higher in number than 20 - Sunken Temple of Qarn, for example. Thats 61 and in his list for me to buy, while the two I've mentioned earlier are missing. So it doesnt seem as if I have to complete the full 80 before being able to buy paintings from 21-80...?