Mike it sounds like you installed something software wise, depending which protocol you allow the router to use, software can alter the ports settings. For example install something like photoshop and it open ports automatically in the router to talk to the servers at adobe, it does this for all kinds of reasons, sometimes however when the operating system gets patched for a vulnerability, it looks for open ports associated with that. in a nut shell it will close the port but the interface isnt altered, so it shows as open. hence why when you deleted it and redid it the router excepts it again.
It could even be software you use specifically for the Ham, it could have updated and closed ports, but at least now you are aware of it and have a goto solution. There is a way of making sure the router dosnt do this, i would not recommend it however. But if you look on the router page you see an option for auto port control, it wont be called that but you should be able to spot it, i am not up on your router and i wouldnt ask for your ip to scan it
It could even be software you use specifically for the Ham, it could have updated and closed ports, but at least now you are aware of it and have a goto solution. There is a way of making sure the router dosnt do this, i would not recommend it however. But if you look on the router page you see an option for auto port control, it wont be called that but you should be able to spot it, i am not up on your router and i wouldnt ask for your ip to scan it