Fix Wedi panels on OSB in wet areas

Hello dear forum members. I had to tear down the green drywall boards in the shower area after 10 years because they absorbed water and some tiles had cracked as a result. Now I want to rebuild the shower area! I have a house built with wooden frame construction and the shower walls (2 sides) are made of structural wood and covered with OSB (rough fiber) boards. Instead of drywall boards, I want to attach Wedi boards to the OSB as a base for the tiles. One expert says to screw the Wedi boards onto the OSB. Another expert says "Oh my God" that this is not stress-free and prefers to attach the Wedi boards with flexible adhesive (notch 8 or 10). There is also the Wedi board adhesive "Wedi 610". Now I am totally confused...... I have to say that our wooden frame house moves very little - in 10 years I have not had any cracks in tiles, grout, or anywhere else! It would be nice if you could give me a little help here. Many thanks