Can't Create In and Out Points For Merged Clips in the Source Monitor

This problem started for me after the most recent big software update to version 14 and has continued with the subsequent smaller updates. When I create a Merged audio/video clip, the in and out points don't work when I'm viewing them in the Source Monitor. When I try to set the ins or outs using either the keyboard or mouse, nothing happens. As a workaround I've been dragging the clips into the timeline and trimming them that way. But I'd prefer to be able to make those super basic trims in the source monitor. Has anyone else been having this issue? Just want to make sure it's the software itself and not something on my end. Using the most recent 2019 MacBook Pro.