I have the same issue and it has been happening ever since I got my 13 Pro Max. I’m running 15.3.1, and the only way I can get search to work again is by force closing the iTunes app and reopening it each time. Otherwise if you try to do a text search the screen just stays black. Even powering off the phone and turning it back on again doesn’t help. You have to force close the iTunes app. You can click on a trending result during this time, and sometimes it opens those results, but even then the search doesn’t respond, so you’re forced to force close the iTunes app again. I feel like there is a bug with the Apple Music subscriptions linked to the iTunes app somehow that is causing this search issue, since I started reliably noticing this happening after signing up for the Apple Music free trial. If you try to cancel the free trial you can’t completely turn it off since it wants to stay active until it expires. I was going to wait to test things after the expiration date for the Apple Music free trial, but it has been too frustrating having to wait months to see if that helps after it expires. There’s definitely a bug with the iTunes search on iPhones, but everyone wants to explain it away with “just force close the app”. That’s not a fix, it’s just a bandaid over the actual underlying problem.