Discrepancies in universal analytics and GA4 analytics data

Question

My project is a chrome extension which is currently sending data to universal analytics dashboard using analytics.js library in event_category, action, label value format While migrating to Google analytics 4 for the same extension as there is no support for gtag.js yet I am sending data using measurement protocol. To keep the universal analytics format intact I have migrated universal analytics event action to event name and I have added category and label as custom dimensions in GA4 so that comparing UA and GA4 dashboards will become easier. When I compare the data for UA and GA4 dashboards I can see from the code that network calls to UA and GA4 properties is happening correctly and for any event or action I can see 2 network calls one for UA and one for GA4 that way it is confirmed that data is getting pushed to both dashboards. But when I actually do the comparisons in the dashboards it shows discrepancies in some event counts and user counts. Difference looks significant for few events. My observation is requests which are made continuous are having some discrepancies in the data while actions/events which are made somewhat single single events those are matching correctly. Can someone help me understand why this would be happening and is comparing UA and GA4 dashboards in this fashion make sense or not? I certainly know that there are fundamental differences in the data formats for UA and GA4 but for this extension I have tried matching category action label with category event_name and label for UA and GA4. Any help understanding why such discrepancies happen and is it acceptbale behaviour would be really helpful.