I first purchased the CAX30 over a year ago and still have yet to find a solid fix for the problem

Be sure to save off a back up configuration to file for safe keeping. Saves time if a reset is needed.
https://kb.netgear.com/24231/How-do-I-back-up-the-router-configuration-settings-on-my-Nighthawk-router
Enjoy. 📡

No problem at all. To make this as easy as possible for you, I recommend going through these steps from a desktop or laptop PC you're certain is already able to connect to your home WiFi network.

- Make sure your computer is connected to your WiFi network.

- From your web browser, visit the router configuration site by typing: "192.168.1.1" in the address bar and press enter.

- To log in, use the following credentials... Username: "admin" - Password: "password" and click Login.

- On the left side of the page, click the tab labeled "Advanced" located directly next to the "Basic" tab.

- Click the "Security" column to expand it, then click on "Access Control".

- Scroll down the page until you see a section that says "View list of blocked devices not currently connected to the network" and click it.

Based on what you showed me earlier in your post, you'll likely see a couple of things in the list of blocked devices. You can fix the problem two different ways. You can either delete each device from the blocked list, or you can completely disable the Access Control feature which is what I recommend you do if you're not concerned with monitoring certain devices owned by family members.

Regardless of which method you choose, you'll want to make sure you click the "Apply" button on the bottom right part of the page to save the changes you made to the settings. If you can find the time to do it, I suggest taking the time to learn all the different settings you can customize in the router configuration site. They will give you better control over the CAX30 and its features.

Good luck!!