After much trial and error, I was finally able to find a setting that keep my Wi-Fi 6 compatible devices on the network.

Solution Workaround (In-Home Only)

1. Login into Router via http://tplinkwifi.net/
2. Click on the Advanced tab.
3. Navigate to Wireless > Wireless Settings
4. Under the Wireless Settings section, change the following settings to static options (don't use Auto option):
   1. Version: WPA2-PSK
   2. Encryption: AES
5. Click Save.
6. Click the Reboot icon to restart your router and apply settings.

EDIT: After an additional day, I noticed that I still have the same issue when I leave and return home. It's not consistent, but about 50% of the time, I cannot reconnect and need to forget the network on my phone and reboot my router. I've added a reboot schedule so that my router automatically restarts before I wake up in the morning.

@CallieLinux 

Is this solution still working for you, it only worked for me while I was still connected, the moment I went out of range (ie leaving my house) it had the same problem when I came back.

@JoshuaJam Not all of the time. Sometimes I cannot reconnect, but other times, I can.

I've also set up a reboot schedule so that my router automatically restarts every morning before I wake up.

Unfortunately, I'm finding it hard to pinpoint the issue since I cannot consistently reproduce the error.

@JoshuaJam 

@Kevin_Z just posted an update on the issue here: https://community.tp-link.com/en/home/forum/topic/180710?replyId=397410. I think he posted the wrong link, but I'm trying the steps in the latest FAQ for the AX3000 (See: https://www.tp-link.com/us/support/faq/2751/).