How often do you lose deals because of the product?

We all know that there are a myriad of things outside of our control and this is just one of them but I’m curious to get SaaS AE’s input here.

How often do you find yourself losing deals over flaws in the product (which can become apparent during a demo, trial, etc etc).

Important to note that I’m referring to flaws in the product, not gaps in services as this might indicate a poor product fit and therefore wouldn’t be too applicable.