Cannot login in paypal app (iphone)

Test driving pi-hole, great app ! however using paypal mobile app (ios) fails, it cannt seems to login.
The perplexing part is that the so host from matching paypal or anything in the logs.

Any way to troubleshoot such situation ?

Try checking pihole -t for the queries made when logging in. I am able to log into the Android PayPal app though.

Its funny none of the domains visited on phone or personal latptop shoes up in the log (I am using vps with dhcp setting enabled). The DNS server are set to the server ip address.

See also this FAQ (it's also useful for finding legitimate domains that need to be whitelisted).