videos from phone not previewing in bridge

I'm not sure if I posted this question in the correct forum last time, so I'm trying again.

I make videos on my pixel 6a. Those that i edit and later download have an LS inserted between the filename, which is a bunch of letters, date and time info and mp4. These files preview in Bridge.

The ones that I haven't endited do not have the LS inserted and they also don't preview in bridge.

I used VLC media player as my default player and I looked at what the codecs are for the different files and they are different.

The native mp4 which doesn't preview is this: Codec: MPEG AAC Audio (mp4a)

The edited mp4 has a different codec: Codec: H264 - MPEG-4 AVC (part 10) (avc1)

What I don't know about codecs could sink a ship, but I can see they are different and as it's the only thing apart from editing that I can find, I'd like to know if there is something I can add to bridge to enable me to preview the videos in bridge, at least a thumbnail as at the moment I have to open the video from bridge to see if it's the video I want. This would be ok if I don't make a lot of videos, but I do.

So please could someone help me.

Thanks