I had this problem with my mini 2 at the beginning as well. What I found out was that the homing sequence to the left does not use any mechanical end stop switches like it does on the z axis (up). Instead it uses some kind of sensorless homing feature in the firmware to detect the end of movement (my assumption is it detects an electrical current spike or something). So when it can’t detect that movement to the left has stopped, it’s because there isn’t enough resistance at the end of the axis to trigger the detection. What I did to fix this was to gently and carefully push back against the print head once it starts to make the “ugly grinding sound”. This increases the resistance enough to hit the trigger. After a handful of times manually intervening like this, the problem went away and I haven’t had to do it since. Maybe you can get an official fix if you’re under warranty, but I wanted to share my solution in case it helps others along the way.