When playing/shuffling a Tidal playlist, only the contents that are loaded/drawn on the app (IE, the first ~30 items in a playlist) are queued. The rest of the playlist is never queued, perhaps unless you scroll to the bottom, thus ‘loading’ the rest of the items in a playlist Tested this, did not work.
What client are you using?
The next set of tracks should load once your reach the bottom of what’s listed in the queue. Try playing or shuffling, open the queue, select the last track, and the queue should extend to include more items.
Also, this issue specifically is the playlist will only start shuffling the first batch of items. So if I hit shuffle playlist 20 times, it will only select from the first batch of songs in the playlist, 20 times.