Video streaming faling again

Using Firefox on a Mac running Big Sur, using Raspicam v1 on a Pi 3.

I was running an old Astrobox image (Jessie) with 17(4) software. I managed to break the micro SD card, so started from scratch with the latest 19(4) image. I enabled the camera in raspi-config, and set it to 720p in Astrobox config (1080 says unsupported as has always been the case)

Video streaming worked a couple of times, then stopped working - just spins trying to start video. It works fine at 640x480, but not a 720p.

Similar to this problem from almost 2 years ago:

Log shows:

2021-12-06 03:53:35,833 - astroprint.webrtc - INFO - Closing all streaming sessions
2021-12-06 03:53:35,836 - astroprint.camera.v4l2.gstreamer - INFO - There are 0 local peers left
2021-12-06 03:53:35,841 - astroprint.camera.v4l2.gstreamer - INFO - Camera detected on /dev/video0
2021-12-06 03:53:35,868 - astroprint.camera.v4l2.gstreamer - INFO - Found camera mmal service 16.1, encoding: h264 and size: 1280x720. Source used: raspicam
2021-12-06 03:53:42,285 - astroprint.camera.v4l2.gstreamer.process.pipelines.raspicam - ERROR - gstreamer error: gst-core-error-quark: GStreamer error: negotiation problem. (7)
— More Info: —
gstvideoscale.c(752): gst_video_scale_fixate_caps (): /GstPipeline:pipeline0/GstBin:img_video_bin/GstVideoScale:videoscale_local_video:
Error calculating the output scaled size - integer overflow

2021-12-06 03:53:42,289 - astroprint.camera.v4l2.gstreamer.pipeline - WARNING - Broadcasting error to ALL pending requests [ {‘details’: ‘GStreamer error: negotiation problem.’, ‘error’: ‘fatal_error’} ]
2021-12-06 03:53:42,291 - astroprint.camera.v4l2.gstreamer.pipeline - ERROR - Error during local video’s frames capture: fatal_error
2021-12-06 03:53:42,293 - astroprint.camera.v4l2.gstreamer.pipeline - INFO - Trying to get list of formats supported by your camera…
2021-12-06 03:53:43,382 - astroprint.camera.v4l2.gstreamer.pipeline - INFO - ioctl: VIDIOC_ENUM_FMT
Type: Video Capture

[0]: 'YU12' (Planar YUV 4:2:0)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[1]: 'YUYV' (YUYV 4:2:2)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[2]: 'RGB3' (24-bit RGB 8-8-8)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[3]: 'JPEG' (JFIF JPEG, compressed)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[4]: 'H264' (H.264, compressed)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[5]: 'MJPG' (Motion-JPEG, compressed)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[6]: 'YVYU' (YVYU 4:2:2)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[7]: 'VYUY' (VYUY 4:2:2)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[8]: 'UYVY' (UYVY 4:2:2)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[9]: 'NV12' (Y/CbCr 4:2:0)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[10]: 'BGR3' (24-bit BGR 8-8-8)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[11]: 'YV12' (Planar YVU 4:2:0)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[12]: 'NV21' (Y/CrCb 4:2:0)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2
[13]: 'BGR4' (32-bit BGRA/X 8-8-8-8)
	Size: Stepwise 32x32 - 2592x1944 with step 2/2

2021-12-06 03:53:43,386 - astroprint.camera.v4l2.gstreamer - ERROR - AstroPrint Pipeline Fatal Error called
2021-12-06 03:53:45,072 - astroprint.webrtc - INFO - Closing all streaming sessions
2021-12-06 03:53:45,074 - astroprint.camera.v4l2.gstreamer - INFO - There are 0 local peers left
2021-12-06 03:53:45,076 - astroprint.camera.v4l2.gstreamer.pipeline - ERROR - There’s no pending [normal/preservative] request for response 1
2021-12-06 03:53:46,263 - astroprint.camera.v4l2.gstreamer - INFO - There are 0 local peers left