After updating to Sequoia 15.3, all MP4s on my system give malware warning

I updated my 2024 Mac Mini to Sequoia 15.3 last night, and now every single MP4 I have gives a "Apple could not verify...mp4” is free of malware that may harm your Mac or compromise your privacy." and my only options are Done or Move to Trash. They will play (in icon) if I click the play control, but will not open in VLC or QuickTime Player. These are files that in some cases I have had for years. Nothing has changed other than updating to 15.3. Do I have any options other than waiting for Apple to address this? Is there a way to rebuild the desktop database or whatever they're looking at here. This is crucial for me professionally.