Google Analytics 4 and Google Ads Conversion Tracking Setup

In January, we setup conversion tracking for our Google Ad campaigns—all phone calls over 30 seconds (call asset calls, location asset GBP calls, website calls) and website "schedule now" clicks. It seemed to be working for a few months, but now calls are no longer being counted as conversions. We need help understanding and resolving the issue. Additionally, we have a Looker Studio (Data Studio) report. This report displays 3 tables: one includes paid conversions per webpage, one includes organic conversions per webpage, and the third displays our Google Ad campaigns statistics (clicks, costs, conversions, etc). We need help making sure this report is configured correctly. This work involves Google Ads, GA, GTM, and Data Studio.