2.4 ghz to 2.4 ghz ping doesn't work but 5.0 ghz to 2.4 ghz works

I have a strange thing happening on a new nighthawk RAX45 router I got. I have some items that connect on the 2.4 ghz band such as a printer, chromecast, grill, etc. What is strange is I cannot ping/connect/print/etc to them with my computers when they are on the 2.4 ghz network but I can ping/connect/print/etc when I am connected to the 5 ghz network. I was able to get it to work for a little while when I changed the channel from Auto to a specific one but after a brief moment reverted to not working. I have smart connect disabled (where the SSID is the same and the router manages if it is 2.4 or 5.0 ghz). Any know what the issue might be?