Apple Music playing songs that is not on playlist

I have only found this issue on my Apple Watch. This is what steps were done to have this issue:

1. Go onto Apple Music on my watch
2. Go onto my playlist and press the three dots.
3. Scroll to the bottom and press ‘shuffle’

As extra description, I have found that it will play songs that are not on my playlist and/or ones I have not manually queued. Some examples of this have been songs in the same albums I have listened to, however some entire artists I have not even listened to on my account before