@ArcherC8 

I actually spent the better part of my morning doing reboots and starting over. I must have done it about 6 times, but it hasn't made a difference. But one thing I don't understand is why I have to keep entering the settings again from scratch every time I reboot. The router I had for two years that I was renting from my ISP never needed that when there was a power outage or if I unplugged it. When power was restored, it just started up and continued on like nothing happened. Why is this one so different? why does it keep losing all its settings when rebooted?  Can you imagine your computer or phone losing everything whenever they're rebooted???

  @terziyski 

Using the image you provided, I only see where it says to enable/disable using the check boxes, and also the hide SSID options. A tried unchecking and rechecking the enable boxes and also using the hide SSID options. All I did was make them disappear off my Wi-Fi list when disabled, but they still come back with an X on them when I bring them back.

But here's some good news I can tell you about it. Using the wireless tab on that page you posted an image of, I did find out where I could change my security protocol to WPA3, which was the original concern I had when I started this thread. Although I'm not sure it makes much of a difference now since it looks like I'm going to be using Ethernet wires to connect my devices from now on. It doesn't look like Wi-Fi is in the cards for me anymore. I plan on returning this router to Walmart on Monday and getting a replacement. It will be the same make and model so I'm not sure if it will make much of any difference. It would if this one is defective. But if I end up with the same luck, I'll need to use cables from now on to connect to my laptop and TV.

  @Nxus 

I just gave that a try now. But my laptop doesn't seem to be very forgetful. I had three networks on the list which included two that related to my current router (and one for the router I returned to my ISP so I wouldn't have to rent it anymore). I clicked on all three of them to forget and they disappeared off the list. But when I then clicked my Wi-Fi icon in the bottom right corner of my screen, my router's ID's still came up and they still had an X on them. It seems that my laptop forgetting them isn't the same as not being able to detect them in the list of Wi-Fi signals that my laptop can still receive.

UPDATE:  Well, I just discovered something interesting. I did another Google search about why an X appears next to someone's SSID. One person on Reddit (in a post from 8 months ago to someone else) suggested that it could be because of a security protocol mismatch between the router and the laptop. That made me remember that this problem started at about the same time I discovered the way to change my security to WPA3. So I just changed it back to WPA2, and now I'm able to connect wirelessly again. I hate to say this, but this brings up another question. Now that I'm able to change my router security to WPA3, how do I change the setting in my laptop to accept it?  This laptop is 8 years old. Is it possible that my laptop just can't accept WPA 3 because my laptop wasn't designed for it to use?  When I Google how to change the security protocol in my laptop, I only get results about how to change it in the router. That makes me think that it's only a laptop issue at this point.  However, my TV is newer and it wasn't connecting to my Wi-fi when it was set to WPA3 either.  It only worked when I connected it directly with an Ethernet cable.

EDIT:  I just Googled when WPA3 was released.  It was 7 years ago, in 2018.  That's after my laptop was made.  But that shouldn't matter, should it?  Security protocols should be backward compatible to some degree.

  @terziyski 

It doesn't appear to be there. But it's interesting that my laptop will work with this router set to WPA3 if I use an Ethernet connection but not a wireless connection. Same goes for my TV. It works fine with the Ethernet cable connected to it, but it doesn't recognize the Wi-Fi signal if the router is set to WPA3. My TV is a few years newer than my laptop.

I should mention that my router seems to have two different WPA2 options. Does it matter which one I choose? One of them is WPA2-PSK [AES}, and the other is WPA2-PSK[AES]+WPA-PSK[TKIP].  Right now, I am using the first one.

Anyway, I copied and pasted what I found in the command prompt. Here it is:

 Authentication and cipher supported in infrastructure mode:
                                Open            None
                                Open            WEP-40bit
                                Open            WEP-104bit
                                Open            WEP
                                WPA-Enterprise  TKIP
                                WPA-Enterprise  CCMP
                                WPA-Personal    TKIP
                                WPA-Personal    CCMP
                                WPA2-Enterprise TKIP
                                WPA2-Enterprise CCMP
                                WPA2-Personal   TKIP
                                WPA2-Personal   CCMP
                                Open            Vendor defined
                                Vendor defined  Vendor defined
    Authentication and cipher supported in ad-hoc mode:
                                Open            None
                                Open            WEP-40bit
                                Open            WEP-104bit
                                Open            WEP
                                WPA2-Personal   CCMP
    IHV service present       : Yes
    IHV adapter OUI           : [00 80 86], type: [00]
    IHV extensibility DLL path: C:\WINDOWS\System32\IWMSSvc.dll
    IHV UI extensibility ClSID: {1bf6cb2d-2ae0-4879-a7aa-a75834fbd0e3}
    IHV diagnostics CLSID     : {00000000-0000-0000-0000-000000000000}
    Wireless Display Supported: Yes (Graphics Driver: Yes, Wi-Fi Driver: Yes)

  @terziyski 

Ok, I'll keep it there.

One last thing:  This is a dual band router.  There's a 2.4GHZ signal and a 5G one.  I've read that the 5G signal is the preferable one to use. I went ahead and disabled the 2.4 GHZ signal since there doesn't seem to be a reason to have it on. I figure it would be just one more signal that someone could hack into. Is it OK to have it turned off?