Been using version 12.0.1 and found a bug when creating transitions. I am in dissolve mode and when double clicking to bring up the transition window, occassionally, I stress occassionally the transition length shows 1 frame. I can stretch this out to the limits but when I click on apply, the dissolve duration of the clip in the timeline dissapears. I have to drag the clip out of the transition and start again.
Once I try it again, I can usually setup the transition OK, just like I have been doing for 13 or so years, but again occassionally this bug comes up again. My current project has many dissolves.