Timber frame structures or really any framed structure is going to move the higher the structure the more the movement. Homes are built to move but when you put waterproofing over a structure is has allot of movement you need to have allot of void to ensure that waterproofing can elongate. If the membrane is only directly stuck down to the surface with intermittent voids in the adhesion only where the cement sheet is then there is not enough allowable movement and failures will occur. It doesn’t matter how many time you pick up and lay tiles down in the circumstance the movement will be greater than the allowable tolerance of the waterproofing and you will find yourself back in the same situation again soon except with less money. There are now external waterproofing membranes that you can install over the tiles. As you will need to retain the same look of your tiles inside and outside then I would suggest the Clear Waterproofing Membrane https://www.remedialmembranes.com/leaky-balcony-repair/ or AUS https://www.remedialmembranes.com.au...alcony-repair/