I updated my filters and can confirm everything is working fine now. The majority of the emails I was not receiving were from one particular site that used mailing lists and not personal addresses in the To field. Since I originally set up email to only forward messages addressed to myself to the device, I was missing all those other ones. I've created an additional filter for that one site and now all emails from them are being received as well.
I've been reluctant to upgrade to .180 but maybe I'll give it a try now