The app stops working for about a minute when opening a new tune. Sometimes the chords don’t display during that time, usually when first launching. Changing keys or even starting a song will locki it up. It is making the app unusable.
Is this a known bug with a solution?
You’re the second person to report this issue in two days, which makes me think it may be a more widespread issue than I first thought. It sounds like something that just started happening, perhaps due to a Android or Chrome update. (I had to deal with an app-breaking update on iOS last year… maybe it’s Android’s turn?)
To anyone affected by this issue: please send me a note from within Strum Machine’s Help menu saying that your app is locking up. Some diagnostic info (version codes) will be automatically included. In addition, please let me know what model of phone/tablet you have, and whether you’ve got a Bluetooth speaker connected. (I’d be interested to hear if the problem persists when the Bluetooth speaker is disconnected, too!)
If I can figure out a pattern (e.g. certain devices that are affected) it will be easier to research and diagnose the issue.
Also, for issues like this that make Strum Machine unusable, I’m happy to give subscription credit to folks who are affected by issues like this that make Strum Machine unusable. I don’t want to take your money for something that doesn’t work properly! 
Hopefully we can figure this out and get it resolved quickly.