Problem with Nexus 9 tablet and Roon remote

All of a sudden, my tablet is having issues connecting to Roon core. I am using a Nexus 9 tablet, (Roon recommended), running Android 7.1.1. Every time I open the tablet, it is not able to find Roon core running on my mac mini. I am running Roon version 1.5 build 354. I have to restart Core on the mini to establish a connection.
I never had this issue before. Is it something in the latest update?