Game Won't Load. Stuck At 'Generating World'

So, I have a Bedrock edition server setup for me and my friends. One of my friend is not able to join the server. Server log says player connected but for him, it is stuck at generating world screen. And nothing happens.

Here Are The Troubleshooting We've Done:

1) Checked whitelist and made sure that his username is correctly entered

2)Tried DynIP

3)Tried Cloudflare DNS

4)Tried VPN

5) Reinstalled server

6)Reset His router

None Of the above method worked. But we've tried connecting with My WI-FI. That time it loaded. So I assume it is a problem with his network. BUT he is able to connect to everything else. Including other Minecraft severs like lifeboat,Mineplex and so on. So maybe it is not the network problem?. Is there any way that this can be fixed?. Tried mailing support. But no reply till now it's been 6 days .

Its an Android phone. Samsung S5 or something.

It is 1.14.60.5 on both the server and client. He had another phone lying around. We tried connecting with it. It won't load if it is his Wi-FI

But every other servers load just fine. It's just aternos