Use a file manager or desktop software to look at the properties of the file to see if there is any embedded metadata (creator, GPS, specific time).
If you can provide the following, I might be able to help further: of the conversation around that video? What contentg., text, people, locations)? How to Add Text to Your Video
Open the specific chat where this file was sent in December 2022, download the video, and view it directly.
On Android, look in WhatsApp > Media > WhatsApp Video . On iPhone, look in your Photos app for the WhatsApp folder.