Does anyone know how to solve this symptom?

[붐아카데미]

Does anyone know how to solve this symptom?

It was recorded on video. plz.. I can't explain it in words. Look carefully at the mouse and the graph.

https://drive.google.com/drive/folders/1KeL_RAcLcvNU8jyUQHPOSQqr86jwg86Y?usp=sharing

[Promidi]

Does this happen on a fresh project with just one MIDI track that is no longer than, say, 10 measures

Also, what are your PC specifications?  (Operating system and build number, Ram, CPU, GPU, etc). 

Are there any tasks running in the background?

Have you considered dropping a note to Cakewalk support:

https://help.cakewalk.com/hc/en-us/requests/new?ticket_form_id=360000025633