Playlist confusion...

[whatever4dogs]

I've been using Musicbee for around 6 months.  In the last week, it's keeps jumping from playlist to playlist.  All my music is in playlists by decade, 50's, 60's, 70's etc, (it took eon's to do!).  One minute I'm listening to banging tunes from UNKLE in the 2010's, the next Abba's Dancing Queen comes on from my 70's list!?  I have other lists for other occasions and let me tell you, it' throws you during... romantic liaison to suddenly have Chumbawamba's Tubthumping suddenly come on!
Have I clicked on something unaware which would allow Musicbee to go on it's own mood rather than what I asked it to play?  Auto DJ is turned off.
The playlists were originally created with Media Player a few years ago, but haven't presented a problem with Musicbee until the last few days.
Thanks in advance for any advice given.

[tjinc]

Hi whatever4dogs and welcome to the forum,

MusicBee can be set to do whatever you want (well, almost) but I'm not sure it can 'go on it's own mood'.
You haven't given us much to go on so far so some more info would be useful:

I assume these are 'static', or 'fixed', playlists (rather than auto-playlists)?
How are you triggering the playback of these playlists?
Could you provide a couple of screenshots:
   1. Your whole MusicBee window (while displaying your playlists).
   2. Your Preferences > Now Playing settings.