Transfer video files (.mp4) from iMac to iPad

Prior to upgrading to Ventura a few weeks ago I was easily able to transfer .mp4 files from my iMac to my older iPad (running iOS12). I'm an artist and download art lessons from my instructor to my iMac, connect the iPad to the iMac, open the iPad in the Finder, select it, manage storage and drag the files onto the iPad. It does indicate at the bottom of the window that the files are being copied; however, the iPad does not show them when I select Apple TV / Home Videos. This is where they have normally resided. By doing this I can easily take my iPad into my studio and do the lessons. This has worked perfectly for years before upgrading to Ventura several weeks ago. I have no idea why this doesn't work. You can see from the attachment there are three lessons on the iPad but when I drag the Canadian Rockies lessons they apparently copy but never show up. Any suggestions. Very frustrating.