Really shouldn’t be necessary between iPhone updates - I also wonder whether we might see seen behaviour when the app data cache starts getting large again.
iPhone crashes after 20 seconds or so used to be very common for me about a year or so ago. It hasn’t done it for me in quite some time, thankfully. I am glad an uninstall worked for you. If it comes back, be sure to enter another support ticket so they know that iPhone issues are back. The Roon team has perpetually been faced with the crash issue. They are getting better at it!