Why does the basis increase?

M-1: "Income recorded on books" which should then flow to OAA on M-2.

I inputted the loan forgiveness on line 5a of the M-1 and it does not flow to the M-2. 

Basis increases as it is treated like tax-exempt interest. 

I entered book income higher than tax income by 10K, then called it "tax exempt interest" on nthe M-1 adjustments sheet. 

10k flowed to M-2, OAA.

There seems to be no other way to get it to OAA unless you manually enter it. No code.