@Jerryb Change your encryption setting to AES ONLY and not give 2.4G devices an option. When gicwn the option support found tgey use the older TKIP encryption. Here are the screen shots again from a post little earlier. You font have to broadcast your SSID.

@samadril Thanks for the reply. I only have like 12 devices max connected at any one time but I will change that setting when I get back home and see if that helps. Appreciate the help!

@MartinKnutson my external storage device just plugs into the USB-A slot but I really appreciate you taking the time to reply. 

@Largeshow it's possible to have a USB 3.0 (which is actually the issue, not usb-c, sorry for conflating the two) that uses a USB A connector at the router end.  The device end can look a little unusual, though.  Your storage device documentation will tell you if it's USB3.  The tp-link documentation states the usb-a connector will support usb 3.0

@samadril so I double checked that setting and it was already set to "AES". I've only had this router for a couple of days and the 2.4 seems to work just fine...until the second I plug something in to the USB port. Thanks again for responding. 

@Largeshow .. Support was pretty responsive, ask maybe they are already aware of the issue. Just a thought. Other post also makes since. Maybe try a different USB device and see if same issue happens.

@samadril ya it looks like I'm going to have to go to support. I did indeed try a different USB device and got the same results. 

@Largeshow so I contacted support and they sent me the following. I made the changes they suggested and it's been working great all afternoon.