Local Server on RPi. App cannot connect to local server

I have setup a local Blynk server on Raspberry Pi on default port 9443. I can access the admin portal on browser. My android phone is connected to same local network. When I try to login or create user on the app after selecting custom server and putting in the server ip and port no., I get a message as " Reconnecting to the server". The message stays for ever and on the admin terminal I do not see any activity.
I checked the port. It shows listening on the Rpi.
I checked my network. Its fine. I can ping my server IP from my phone without any loss of packets.
Any ideas?

I searched a lot on the forum but none seems to have encountered any issue at this stage.

Are you able to log in through the app using the default user name: admin@blynk.cc and password: admin)?