Hopper overflowing - connection question

[ianjimjim]

Hi all,
Apologies for the poor quality photo. I recently had some new guttering installed and ran into issues with the hopper overflowing. Can anyone shed some light on how the hopper is supposed to drain? I can see the downpipe going in to the hopper but can't see how the hopper water would flow into the downpipe. Is there just a very small clearance at the base of the downpipe into the hopper that i can't see? Should there be a hole in the side of the downpipe?

The white pipe to the right is from my bathroom. And yes, I need to call them back in to fix the hopper to the wall properly!

Thanks for any feedback!

 

[datarebal]

Either cut the top pipe shorter or at least cut a 45 on it . It will constantly block as is

 

[noseall]

Ditto, shorten the incoming DP.