I finally managed to reproduce and fix the bugs that were occurring for many people after upgrading DaTuner, so please try the latest versions on google play and let me know if it works for you!
Pro:
https://play.google.com/store/apps/details?id=com.applicaudia.dsp.datuner_donate
Beta (testing the Pro version with ads, updated often):
https://play.google.com/store/apps/details?id=com.bork.dsp.datunerbeta
Lite:
https://play.google.com/store/apps/details?id=com.bork.dsp.datuna