That's weird... I'll go through what it should look like, and we'll see what's wrong...
When player reaches a point in the game he wishes to be able to teleport to, he can press a button to remember it, am I right? First of all, not always do common events work, and I would recommend having a switch for places he must not be able to return to. Use, maybe... the L button (that would Q). Use a conditonal Branch for this.
The use a Variable Control command, that remembers the current Map ID in a variable, and a different variable for X and a third for the y coordinates. Simple enough. So when the player presses Q the Map ID and his/her exact coordinates are remembered. Now with another Common Event (have a parralel switch trigger here as well- why not the same as before...?) do so that if the Map ID variable is 0, then nothing happens. If it is larger than 0 then you use a Transfer Player command to the Map ID and the X and Y of the player's remembered location. You seem to know it, but maybe you accidently missed something?
If it doesn't work, you might want to try to have 2 parralel process events on every map in the game
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