I run advertisements (SEO) for a client via Google ads, and my conversions aren't working. I've double, triple checked everything, I've tried the conversions via Google Analytics, that didn't work (I would get data such as user time spend on page, but not conversions), and quite frankly, I am unsure what to do.
I allowed for at least a full 24-hour period to test out the conversions, I have tried troubleshooting via Google Tag Manager, and I have already asked for some help.
You could try the Google Tag Assistant extension. It is what I used recently to verify that the Google Analytics tracking tag was present during our Checkout & Order Confirmation pages. It is also possible, though unlikely, that everyone who has made a purchase so far has refused/rejected the tracking cookies in some way.