Sometimes there is no problem when music is clashing with SFX. It depends on what type of SFX you create. It is hard to give you a proper advice without hearing your music/SFX. There are thousands of variations.
You can make atonal or non-musical sound effects for example. But there are SFX that clash with music harmony but cause no earache
Look for another game examples.
This game has lots of tonal SFX. And no one is clashing with music so much.