so I was testing a few mods and started having weird issues with Bambo. when I turned DH off the issue got fixed but I want to have a high render distance without actually changing my render Distance the settings render distance up
so please fix this bug
thanks.

As the person above explained, this is not caused by Falling trees.
Falling trees do not make any changes to blocks before they're mined.

So is there any solution to thus problem?

This is not an issue with Panda's Falling Trees, you will have to ask the creators of Distance Horizons to help you.