Can anyone explain why I can pick up node 100 miles away but not 3 miles away

[SS72post]

Hi I have just started using meshtastic and finding it really interesting. I live in the south UK just north of Bournemouth. I have picked up nodes down in Cornwall about 100 miles away. But struggle to pick up my friends node and he live 3 miles west of me.
So far I have picked up about 90 nodes most in Devon and Cornwall area so all east of me. But only 3 east of me. Yet my friend that live 3 mile west of me can pick up nodes east of me no problem.

I have set up an high gain mast antenna outside as high as I can so my signal is reasonably good.
We have made sure both are board are set up exactly the same on the same frequency and frequency slot and both on long fast.
I have been able to pick up his node a few times but its not very often.

Can someone explain how we con both pick up nodes further away but not one nearby.