Q: "Up Next" in iTunes- how do I play a voice memo without clearing my queue?

In iTunes, when I've added a bunch of songs from my library to "Up Next" and then decide to play a voice memo, the entire "Up Next" list I've created somehow gets completely deleted without me being able to retrieve it or even see the songs I had queued up. Can someone please help me figure out why this keeps happening and how to stop it? I'm thinking since the voice memo files were added to the library from synching my NEW iphone to my computer, that maybe playing this type of file from a new device resets the list. I'm also not able to add these voice memos to the Up Next list at all- so when I double-click on one to play it from the song library, that's when the existing Up Next queue gets cleared. Any ideas would be much appreciated!

Thanks so much!!!