Longtime deezer premium subscriber. This issue has been bugging me for a very long time one year or so and after reading some steps I’ve troubleshooted it in many ways.
I have iPhone 11 Pro now (had the same issue on iPhone Xs). This happens very randomly but very frequently as well, whenever I play my music from favorites (this is my default listening habit) it crashes without any error or whatsoever. Most of the time this happens during the first/third song after I launch the app. As I observe after I pass let’s say 4-5 songs the app is much less likely to randomly crash. But if it does crashes on the first song the app, most of the time I have to relaunch the app and start listening, app is still going to crash most probably. One remedy that works 60% of the time is when I launch the app, start listening and then never lock the screen for the first few songs, but then again there are instances it crashes in these situations too.
Solution would be nice for this, because it’s extremely annoying. Added some other issues here and there within the app tips me to switch the services, which I really don’t want to do as I’ve been subscriber from my previous account since day 1.