Ron, provide your topology. There is instruction about how to configure PPTP server. Try to check your configuration step by step. http://www.tp-link.com/en/article/?faqid=385

Your printer supports airprint? If so, maybe the latest firmware of WPA4220 can fix this issue. http://www.tp-link.com/en/support/download/?model=TL-WPA4220&version=V1#tbl_j

Neither of them are in compatibility list of MR3220. http://www.tp-link.com/en/support/3g-comp-list/?model=TL-MR3220&location=1249 It is suggested to test before you buy them.

There is an instruction to configure firewall settings on W9980. http://www.tp-link.com/en/article/?faqid=467

Read this article. http://www.tp-link.com/en/article/?faqid=603

Different APs and your main router are using different SSIDs? Try to fix different channels for all of them. What's the operating system of your laptop? To figure out where the problem is, you may...