How to scan for the Pegasus spyware with Debian/KDE & Android: getting " [mvt.android.modules.adb.base] Unable to connect to the device over USB."

On my Debian11/KDE machine I ran pip3 install mvt --user then I enabled developer options on my Android smartphone (via tapping on the build-number a few times), enabled USB debugging on it, connected to the computer with the fully functional USB cable that was shipped with the phone, ran mvt-android check-adb and confirmed the popup on the phone asking whether the RSA key of the computer is to be trusted (without checking to always trust it). Basically just like described in the docs here . I also tried after selecting using it as MTP device and mounting it (but MTP should be disabled for this afaik) and also ran adb kill-server before the above command. However, it always fails with this output:

MVT - Mobile Verification Toolkit
                https://mvt.re 
                Version: 1.2.10


         INFO     [mvt.android.cli] Checking Android through adb bridge                                                                                    
         INFO     [mvt.android.cli] Loaded a total of 0 indicators                                                                                         
         INFO     [mvt.android.modules.adb.chrome_history] Running module ChromeHistory...                                                                 
         ERROR    [mvt.android.modules.adb.base] Unable to connect to the device over USB. Try to unplug, plug the device and start again.

Running adb devices does show the device: it shows the id and "unauthorized". Before I ran adb kill-server it showed "device" instead of "unauthorized" (I got CRITICAL [mvt.android.modules.adb.base] Device is busy, maybe run 'adb kill-server' and try again. when running it when it showed "device"). Do I maybe need to run sudo adb start-server or something like that? There always has been an issue with establishing an USB connection with my Android phone and keeping the connection up for long even with another smartphone and other USB cables and other USB ports and another Debian/KDE machine, but it usually works after reconnecting a few times and selecting "Open folder" in the popups of the Dolphin file explorer multiple times (usually not long enough to transfer many files or browse files on the phone conveniently but somewhat good enough). Edit: it usually works if Dolphin is closed before mounting. How to solve this? --- Edit: created an issue here . Now it does run through but shows no results, shows one error and MVT can't be upgraded (another issue there).