How do I remove this material with Trim/Extend

Hello All.

I'm struggling with trimming the body shown in the picture below. In this weldment, I run into this scenario multiple times. I don't remember having this issue with 2018 but after upgrading to 2020 sp5 I feel like no matter what I do using the trim extend feature I can't get it right. Any help would be really appreciated. 

SolidworksWeldments