Cutting and Extending loops with/without Quantize

If you set a loop and want to extend it, if quantize is ON the loop is just extended from the point where you pressed the extension button and playing is not resumed from the beginning of the loop. On the other hand, if quantize is OFF each time you extend or cut a loop the loop is played from the FIRST beat set (beginnig of the loop).
I wonder if this is correct. Why, if I don't use the quantize feature, the loop is started from the beginning even if I asked for an extension?
I think that in both cases, quantize ON or OFF, the loop should be modified and palyed from the point where the command is issued/pressed. No need to jump to the beginning unless the loop is at the end point.
Thanks
Alberto