Hi-Def stream events won't play: Black box with error indicating server problem or that the format is not supported

[GivingItMyBest]

I'm running 1.34 on Ubuntu 20.04 with 24gb ram.

I have 2 streams from the same camera, one is a lower resolution stream to trigger events and always record, the other is a 2699x1520 stream. Bothworked fine as JPEG; however, when I switched to x264 encoding, only the low resolution stream will play. The high resolution stream (in Firefox) is a black box with an X and the error "The video could not be loaded, either because the server or network failed or because the format is not supported". I found instances of this reported in prior version, but each was indicated as fixed in version 1.31 and higher. Any help would be appreciated.

[GivingItMyBest]

I forgot to include the source is a Hikvision 6mp dome camera.

Any tips?

[GivingItMyBest]

Does anyone have any ideas or is there any other information needed?

[iconnor]

How about logs? how about a sample video for us to look at?

[GivingItMyBest]

Lowering the frames from 30 to 25fps seems to have fixed it.