I am having a hard time finding the right seating position in the C and GLC class, with 3 zone adjustable lumbar support. Within minutes I am starting to have back pains, that I don't have in other cars. I seem to be particularly bothered by the bulge in the lower back, below the lowest lumbar support cushion. GLC seems a bit better than the W205 I drove prior to this, but I actually hoped that the higher seat of the GLC would totally eliminate the issue. Some other cars have this "ahhhh" feeling when you sink a bit into the seat. What should I do to adjust the seat to have a similar experience in the GLC? Or what am I doing wrong?

Edit: I am not that tall, just 1m79, but about 95-100 kg.