Randomness of adjustment handles?

Greetings! I am new here, so pardon any stupid questions. I do have a slight dilemma. The sheer randomness at which you can adjust the positioning of objects. The instructions say- click on the object and when you hold down shift the “adjustment bars” allow you to change the spacing. The problem is that seems to only work one out of 8 tries for me.

what am i doing wrong? i just want to shrink/shift a text box. i can move the left side, but not the right… help?

thanks

Scott