REGRESSION: No, this also occurs in 4.15.
In the montage editor, the gree montage section bars render behind the black lines of the timeline, making them hard to see.
In the Montage timeline, the green bars indicating the montage sections are behind the black lines and are barely visible.
For the green bars to render on top of the black lines.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-44081 in the post.