Using autofill CRA info shows a RRSP withdrawal of 5000 (4500 and 500 withholding) should be 15000 (13500 and 1500 withholding) how do I fix within turbotax?

It depends on the time, AFR sometimes does now have all your info from CRA. 

if you see AFR missing info, please manually enter it in the corresponding slip/form.