Audit Engagement Tracking First
The 48-video report shows 0.0% ER, 0.0 median likes, and 0.0 median comments despite 470500.0 median views, 87,671,785 total views, and a reported 61.7:1 like/comment ratio.
Details
Before changing formats, reconcile YouTube Studio with the exported data for all 48 videos and recalculate each video's ER so the 0.0% result is trustworthy.