I don't think it is because of the relay choice, I think the problem here is in the "private" nature of the payment, maybe the wallet used and therefore the corresponding LN payment needs to be done in a way that is recorded as coming from the right nostr profile, so that the event can be associated with it and then be displayed/retrieved. Otherwise it is considered a "rogue" payment, but this is just my two cents. 

 Hum..
Accodiing to NIP-57 (the implementation of zaps), notes/events include payment related tags, of which include the amount, lnurl and also relays. My understanding is if a payment is received on that address (unique to the post), it is known by the relays included.

I can't see any zaps on these posts from you, but I did receive it - Did you zap a specific post or my profile? If it was a post, can you link it? 

 It was this post: nevent1qvzqqqqqqypzpte8562wrm20dljp9yqnnfypnvvzmsumalvas40hrq5923km5ly0qy88wumn8ghj7mn0wvhxcmmv9uq32amnwvaz7tmwdaehgu3wdau8gu3wv3jhvtcqypuyg9wz485xtsxc9fw88zpmtl9cg4gnrn7allryac7whpn4vft8sjkvgwr 

 I did some troubleshooting yesterday on an issue that may have been related, essentially some inconsistency with how my LN address worked. It may have had an effect on this particular issue, so if that's the case, shouldn't happen anymore. Otherwise, really don't know.. 🤔