How do I reset my HomePod mini to fix playback issues?

I own two HomePod mini’s and use both with the same iPad. One is in my garage and no matter how long it’s been since I last used it when I tap it on it picks up right where it left off on a playlist or album I was listening to. The other is in my bathroom and I use it every day. When I tap it on it puts a whole new playlist together. How can I get it to remember what it was playing and pick up where I left off? I looked at the user guide and couldn’t find anything. TIA

[Re-Titled By Moderator]