SX4 S-Cross – Entertainment system: dull sound in FM mode

I’ve been a happy owner of a new SX4 S-cross for 2 months. One thing I noticed, however, is that I haven’t found anything on the net yet. There is a very strong sound difference between DAB and FM on the radio. While in DAB mode the sound is brilliant and normal in my eyes, the radio in FM mode sounds extremely dull. This is especially noticeable when the two modes are switched back and forth because of bad reception. I already realize that the radio has a lot of fun. there are differences in quality between analog and digital radio, but to this extent I have never noticed this in other radio models. Certainly you can regulate the sound, but only in general and not for each mode of operation separate. Has the other already noticed, or is there a solution for it?