ALT-Y not working

A function I use a lot but is not working 100%. Problem can be seen by downloading this clip
https://we.tl/t-e0aliVIQcy
https://we.tl/t-e0aliVIQcy
https://forum.blackmagicdesign.com/
https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=78072