Right foot big toe feels immediately numb in certain shoes and perfectly fine in others. i think it my be hight difference from heel to toe.

Poosibel: But more likely that when it goes numb you are wearing a narrow toe shoe that puts pressure on the nerve.

Keep in mind: One size for one company or brand does not necessarily equate wi th the same size in another brand, so you want to make sure the shoe fits properly. I would add, sometimes, pain to the big toe can be a sign of lower back pain. So keep that in the back of your head as well.

Numb: Both good answers , so you can see no problem has just one cause or solution . See your podiatrist for help.