Looks fine. Good strong signal. Nothing there to change.
Bad DNS would be using your ISP DNS and it is too slow or has bad information. A lot of people use alternate DNS servers like Cloudflare (1.1.1.1) or Google (8.8.8.8) or Quad9 (9.9.9.9). I use OpenDNS servers instead of my ISP at the router. That way all of my devices get the better DNS.
I see your router is blocking encrypted DNS. That could be because you have Traffic Analyzer enabled on it, which requires that it has access to all DNS queries. Disabling that could make DoH and DoT encrypted DNS queries successful. I am not here to instruct you on router configuration. But you can also bypass this by setting the DNS servers above on your devices.
Probably not a dying access point, but it could need a firmware update. There have been a lot of hacks on routers recently and the firmware updates stop a lot of the attacks. This is pretty advanced and if it is done wrong the router will no longer work. If you decide to look at firmware updates, follow the manufacturer instructions exactly.
Flaky ISP is something that could happen at any time. If the ISP is having internal issues with their network, it will impact their customers like you. Not much can be done about it. Some sleuthing can identify bottlenecks in their network and calls to their support could get them resolved. Not going to provide more information on this either.
Based on past discussions, all these troubleshooting items are way beyond your skill. You should get with the person that manages your network and see if they can determine the causes of your issues, and make changes.