@kilfinan 

Hello, we can look into this, but we would need some more information, we hope you could help:

1. When you are mentioning the connections drops on the VR2800, are you connected to the 2.4G or 5G network on the phones, Fire TV or Sonos?

What channel are you currently using and what channel width (20/40/80MHz)? Try to run a Wi-Fi analyzer to look for a clear 2.4G and 5G channel, it will show you the nearby APs and what channel they are using. 2.4GHz is a very congested range generally so avoidance of the neighbors can be difficult.
 

2. As per your description, it seems that the disconnects happen randomly on different devices, can you confirm if that specific device is still connected to the network, or it is disconnected from the network when the internet drops? If it still connects to the network but shows no internet, please check if it still gets a correct IP address from the VR2800, you can also try to set a static IP on it, then confirm.

Additionally, please refer to the troubleshooting guide below to narrow down the issue:

https://www.tp-link.com/support/faq/2238/

Have a nice day.

@kilfinan 

How much internet bandwidth you could get from the internet service provider, especially the upload bandwidth? Please show us the DSL status page on the VR2800, thanks.