I don’t have this problem, but I tried to reproduce it.
The 150b plays music from a queue. Whenever you tell it to play something, it goes into the queue. In settings, there is a MUSIC OPTIONS setting that tells the player what to do with what you selected. On my machine, I have this setting to LISTEN NOW which places what I have selected to the bottom of the queue and starts playing it - so with play all the entire album is placed in the bottom of the queue, and all prior played content is above it.
Another factor is the settings on the queue itself. There are settings to shuffle the items in the queue. There is a repeat option too. These are icons in the queue.
One last factor is AUTOPLAY from the recommended playlist. This toggle within the queue itself will suggest and start playing items that are not in your current queue, but are suggested items that you may like.
So with all of the above settings, I was able to reproduce a similar scenario to yours. I had items in my queue to listen, I selected a new album to be played and my next song was from my prior content in a random order.
You should check these settings noted above. Some or all of them may be driving your situation.
If you want to reset your queue, I suggest that within the queue, you select all items and delete the queue. That should clear things up. You can then also check the other settings to determine how you want playback to occur - shuffle, repeat, etc.
The playback queue is one of the most powerful but confusing features of the Rose system. Once you set it properly, it is extremely powerful as it provides a dynamic playlist of sorts.
You may also want to look at the MUSIC OPTIONS setting. There are lots of options including the ability to clear the queue and replace it with what you just selected.
I hope this helps.