I received a CP2000 stating that I may have an understatement in my income for the tax year 2015. I am still preparing my response. Will they withhold my 2017 refund?

 I spoke to an IRS CSR and they stated that it looked like the system did not accept an Education Credit.  I have the applicable form. Should I wait to resolve the 2015 tax issue before filing my 2017 taxes? Will they automatically take my 2017 refund?