DDJ FLX4 midi mapping

hi , i have an problem with mapping on rekordbox, on my FLX4 the FX2.1 BEAT UP/DOWN ar not responding suddenly so i wanted to remap it because reset to default did not work, i tested the flx4 with midi-OX and knob working fine. so when i deleted the FX2.1 beat up and down for remapping a message says that its already mapped to FX1.1 .i notes that the mapping name of FX2.1 was different than  FX1.1 wile there is only one for this on the FLX4 so how do i map FX1.1 and FX2.1 to the same knob ?

now at this moment trying something and FX2 NEXT button on FLX4 also not responding suddenly

and again after reset still not working. it seems to me that only the hardware midi gets reset but not rekordbox midi message where hardware needs to connect to, otherwise it should reconnect the way is was before the problem appears. so what's goin on here. do i need to reinstall rekordbox to be sure that the internal midi settings are correct again if this is the case ?