Here’s the wonky gear knob in question. It moved a good 90 degrees.
This is why I replaced the gear knob on my 4/4 (identical to that pictured) with one that has no markings. There is no correct orientation.
But at least with markings, it gives a forewarning that it is becoming loose before it suddenly comes off in your hand…(and then won’t simply slide back on until the grub screws are eased back.) I do a “twist check” as one of my annual service items, as it doesn’t stay tight forever.