Flowerman is right on the amount of force required. The leap of faith you have to make is that the clamp is set to the correct amount of torque when the crossbars are delivered. In my case, the force required for the first one resulted in the outer cover slipping, breaking off the small...
Curious if you tried a soft reset by holding the volume knob down until screens go black and reboot. That would be an easier fix to attempt, similar to what Teslas need from time to time.
Apple Lossless should be a file with a .m4a extension. According to the owners manual, that should be fine.
File extension
.mp3;.wma;.asf;.m4a;.m4b;.aac;.flac;.mpg;.mpeg;.avi;.mp4;.m4v;.mov;.wmv;.3gp;.mkv;.ts;.mid.xmf;.mxmf;.rtttl;.rtx;.imy;.ogg;.webm;.wav