Hi @raphaelarias,
I hope all is well with you 
When looking at the webhook event subscriptions you created on your app 62980, I noticed that the property pipelineStatus isn’t the same as the internal name of the pipelineStatus property created on your HubSpot portal 493376:
The internal name value is pipelinestatus (small ‘S’) whereas the webhook event subscription is using pipelineStatus. This is likely why you ain’t receiving any notification when the pipelineStatus property changed.
On my end, I tried creating a similar custom property and I was able to see that the webhook notification was sent out just fine when I update the custom property.
I hope this helps to clarify!