Casio mt-540 midi channel change help

my 606 with qs upgrade can’t change midi channel because the tap write button is broken, and i can’t seem to stop the casio from receiving midi on channel 1, how do you change the channel of the casio to stop receiving on one and only receive one 2? (instead of 1 through 4)

thank you

PS - there seems to be an unwanted midi feedback loop between my digitakt and korg monopoly (with midi).

ideally i would like the korg to be able to play the ob6 desktop through the digitakt, be able to enter notes into the sequence, and be sequenced back by the digitakt.

however, there lots of glitches and things not working right. would a midi thru rack fix these problems?