I thought that the video element can be considered for LCP if it has a poster attribute set.
In this case there is no poster image but the LCP data points to mp4 file.
How come?
Could probably tell better with the full details but Chrome is also working on changing that so a video can count as the LCP element based on the first frame of video: 1289664 - chromium - An open-source project to help move the web forward. - Monorail