Jardee

Thx for that Sean, 
I found it difficult to find any clear info using search engines, as once the abvr. "VPN" Is used, the results are all adverts or honeypot reviews. I previously found a similar situation to you, I retested today to confirm. and found -  pic CF1

However after I installed  the latest version of the app,
My attempts seemed to show that the cloudflare DNS is now in use, -  Pic CF2

I lost access to the WARP+ function of the CF apk - I mistakenly reset it when looking at the logs!, so couldn't test further.

Also if a VPN is active on the Hotspot Provider it seems unable to provide an I.P. to the Hotspot Client, but if I momentarily disconnect the Provider VPN an IP is assigned to the client.  A VPN will then operate successfully on the client, I used the Nord Apk. 
If I understood your answer properly this is the way to do it?
I'm probably wrong as I'm figuring it out as I go.
 A huge Thank U for the Editor site - I am amazed at your generousity

I had the same problem when using WARP trial 10Gb. and gave up on it.
Does this mean that the Warp traffic is not encrypted or....
And that it should work if tethered to a phone using 3?
thx +