What's the reason behind the absence of conversion data in our reports?

To be able to view these data, there are a few steps that need to be taken.

Firstly, under Settings > Event Definition, you need to save the situations you want to count as conversions as segments.

Secondly, click on the Delivery Settings option located at the top right of the campaign creation screen. In the opened popup, go to the Conversion Tracking tab and activate the Conversion Goal option. Then, from the Conversion Event field, select the event definition you defined and save it.