Coinos DOES in include the lud16 while Cashu does not. Since he's using the Coinos NWC string, the lud16 is overriding the LN address he has setup in his profile and zaps are going to Coinos instead of Cashu. With the manually updated Cashu connect string set as NWC, sending and receiving zaps should now go through Cashu as we intend. I'm just waiting for him to execute these instructions and we'll see if it works properly
So that would mean that if Coinos included the lud16 in their connect string Damus would use the associated Coinos LN address to receive instead of whatever LN address was set in the profile?
OK, so I looked at the Coinos connect string and it does include the lud16. That means the Damus is using that instead of the defined LN address from the profile (the Cashu address). If we manually add the Cashu lud16 to the Cashu connect string and paste that into Damus, it should work properly then, correct? Because that makes a lot of sense based on what you've said.
I'm going to have him do that and we'll see if the problem goes away. Thank you very much for taking the time to help with this problem. I appreciate your expertise and assistance.
What do you recommend? Should I have him re-paste the connect string into Damus?
The NWC connect string was copy/pasted directly frokm Cashu without alteration. It looks like this:
nostr+walletconnect://c6287894d0731059634ba912930f4557dd41ca7be1f32d6cacf398288125e361?relay=wss://relay.primal.net&relay=wss://relay.damus.io&relay=wss://relay.8333.space/&relay=wss://nos.lol&secret=
And when he tries to zap himself, in instead of going from his Coinos to his Cashu, it's just being sent from Coinos and then received by Coinos. It's as if the LN address he's got set in his profile is being completely ignored and somehow his Coinos address is being used as both his LN address and his NWC.
That's what I thought. But he's got his Cashu Wallet LN address set I his profile, and Coinos set as NWC, but when I zap him his goes to Coinos. I don't know how else to explain that.
And now it seems that Damus is ignoring the LN address he's got set o his profile and is routing all outgoing AND incoming zaps through NWC?
Wow. Then Damus is actually ignoring your zap address and routing everything through your NWC. As I said, I've never heard such a thing. I'll tell you, after all this nonsense, I'm starting to dislike Damus. First it's not working with Cashu, and now it's ignoring the protocol and routing everything through NWC. This is disturbing all the way around.
I don't see how that's possible. You have your Cashu address set in your profile so any zaps should go to Cashu. There's no pathway to Coinos since you're not using Coinos address. Unless Damus is somehow ignoring the address you have set In your profile and is routing everything through NWC? But I've never heard of such a thing. Double check your Cashu Wallet.
No deaths is always good.
Can you check to see if you received the 11 sat zap I just sent your way? Just wanna make sure the zap receive function is working. The last sats I successfully sent was a manual lightning send from my wallet to your bfgreen@npub.cash address.
I the meantime, you can use Cashu to receive zaps, and Coinos as your NWC provider. It's not ideal, but it's a config that will work and keep you open for business and able to zap while we work it out.
This is really frustrating.😡 We're gonna get this working. We just have to keep beating on it until we figure out the problem. Brute force diagnostics. Don't give up!
I just successfully sent sats to your bfgreen@npub.cash address. Go into your settings and confirm that you have the "receive automatically" toggle enabled right under the "enable payment requests" toggle. Then go back to your main wallet screen and refresh the wallet using the little refresh button in the top right corner.
nostr:npub1vkgj57k30l2u7wave6t4nua75wjylx3nju6qu4vu7pneghwx8zlsf7q4uq yeah, my new npub.cash address showed up in my cashu wallet settings. Well NWC to Damus via Cashu wallet let me zap one time. Now no dice again - but I’m excited to see how it worked. 
Well, I'm glad you got the lightning address sorted out and working right. Now we just have to figure out why your ability to zap seems to be intermittent. I'm wondering if it's a routing issue between Cashu and some lightning addresses. Try zapping the person you successfully zapped before to see if it goes through, then zap me or someone else with a different zap address.