Only one go my apple devices (iPhone) cannot connect to 5g with AX6 AX5400

I've had this netgear router about a year without problems. But for about the past month, my desktop, my chromebooks, iPads, use the 5g with no problem, yet my iPhone just cannot connect to 5g. I just can't figure it out.

When I try to switch my iPhone to the 5g, it says 'no internet connection.' Yet at the same time all my other devices remain connected to 5g and work. Just the iPhone. 

I thought it could be a vpn issue but the other devices use VPN and still connect.

Any ideas? Why would all the devices connect to 5g except my iPhone? I can't figure it out. It must have something to do with settings on the iPhone itself right? But I don't remember switching anything.

The only other thing, that is probably not related, is a big rain storm came through about a month ago, and that's roughly when I noticed the issue starting. There was some outages and then everything was fine. But about that time is when I noticed that only one device can't connect. But I am on my iPhone the most

If any ideas please let me know!

thank you!