Hi straykatzz857
First off let me welcome you to the site, and to WinMX. There is not central server so when your forwarding ports its for opening ports from you to other users. WinMX is completely decentralized.
If when your using primary you have searches fail this is because something is blocking your UDP port. Your TCP port may also be blocked but the symptom of this is no uploads work. Secondary relies on the Primary its connected to for the UDP function and there for works fine.
The most likely beast to be blocking those for you is a router or NAT capable DSL modem. First thing to do is make sure you have ports open sepcifically for WinMX and as you have read you need two, one for TCP and one for UDP for a primary to work right. Have a look here for instructions:
https://www.winmxworld.com/tutorials/routers_info.htmlThe next would be firewalls, in most allowing the program access is enough however a few are finiky. Have a look here for instrctuions for yours:
https://www.winmxworld.com/tutorials/firewall.htmlOnce those are all set if your still having problems post back here, or if you have any questions about the above.