Problem when using subsurf/mirror

I’m new to Blender so please forgive me if this is a stupid question. I keep getting these weird seems showing up on my models and I’m not sure how to deal with them. They are with mirror on and subsurface on. Where the typology meets the mirrored surface the face bends one way or another. I have clipping turned on and the faces look normal with subsurface off. Also I’ve tried to recalculating normals to some extent. I’m sure this is some basic technique I’m missing, but if anyone can help me I would be much appreciated. Also I hope I posted this in the correct forum. Apologies if not.

Ensure you have the mirror modifier above the subsurf modifier and in the mirror modifier you have enabled ‘merge’ with a big enough merge factor so the centre vertices merge together

Ahhh I will check that! Thanks allot!