Won't play part of playlist in shuffle

[dedhed333]

Plan

Premium

Country

UK

Device

Windows 10 (exact same issue on Android with the same songs in the playlist)

My Question or Issue

I have had a playlist for a while now and recently added another album to it, but noticed that none of the songs from the album were playing, after looking around this seems to be a shuffle related problem because taking shuffle off fixes it, but its a playlist of albums so I want to shuffle.
This has also happened regardless of what device I was listening to it on or started playing from. I had added other songs to the playlist just a week before and they seem to be fine in shuffle.

I also think that this might be happening in another playlist but that one is too big for me to definitively say, although I definitely feel like I hear a far shallower pool of music than I should.
I have removed and readded the album but this has had no effect on this problem.