Why do I get iCloud music library has expired?

Why do I get iCloud music library has expired?

When ever I wake my Mac from "sleep" or access iTunes after not using it a whaile I get, "Your iCloud music library session has expired." and I have to put in my password again. Once a day I would not mind but sometimes it is 15 times a day! I had iTunes Match for the past couple years but stopped in December. The request has come up since then. Please help me to stop it!

Thanks!!