Bounding box select in NLA editor not working

Hello, I was working on my animation and using the nla editor when suddenly the bounding box select too (“B” on keyboard) stopped working correctly. For some odd reason it doesn’t select the frames in the bounding box, it selects the frames slightly below the bounding box. I restarted blender and made a quick test file by animating the default cube moving and the bounding box select tool worked in the nla editor. But when I reopened the file for my animation, the b-select tool is broken again. Any ideas on this?