There is another issue, that might be related to this, that affects my 2 PS4s connected to this same network. This morning when I noticed that my 2 PS4s were not showing that they were connected to the network. Physically they are connected with a wired connection. But when I use them they are not. When I check the client list on my RT-AC88U, they are not showing up.
The work around to get them connected is this.
1 - On the PS4, goto Network setup and choose Wireless.
2 - Go through the steps of attempting to connect.
3 - My wireless connections for 2.4Ghz and 5.0 Ghz are choices on my PS4 PRO, and just 2.4Ghz for my PS4.
4 - Both consoles attempt to connect wireless but are unable to. Normally they should be able to. Note: This is okay for this workaround.
5 - After getting failed messages on the previous step, change the PS4's connection in software to a Wired connection.
6 - Devices connect. Everything works well after this point.
I'll use my PS4s for a couple hours. Then either shut them down or put them in rest mode. It may be several days to several weeks before I use them again. If it's just a few days between usage, then they are likely to still be connected to my network when I use them again. If it's a longer duration, then they are likely to not be connected. And then I have to do the above steps to get it working again.
I got my router about 2 years ago. It worked awesome for most that time. But a few months ago, it started doing this. And then a few weeks ago it started doing the issue with my PC. We also noticed a couple weeks ago, that when a friend came by to connect their laptop wirelessly to one of our 2 wireless connections, that they can't connect to our network. Despite the 2 spots showing up. Running a wired connect allows them to connect. Our other phone devices seem to work normally. But I'm not sure if they lose wireless, and then use cellular to connect to the internet, or not.
Another friend of mine suggested to get a new router.
EDIT : I don't think I've tried a factroy reset of the router yet. I think I'll try doing that.