Where performance is measured, performance improves.
Where performance isn’t measured, performance will not improve.
Now read the above sentences again, with machine learning in mind.
Moral of the story: be sure to track all of your conversions.
– Nils
PS: Here are two quick links to help you track more conversions:
https://support.google.com/google-ads/answer/2998031?hl=en
https://support.google.com/google-ads/answer/9888656?hl=en