starbasessd

If you add the Pi4 WebCam As Network, URL: rtsp://ip_address:554 Username admin password (blank or whatever you set it to) try both RTSP/TCP or RTSP/UDP for camera What results do...

I run 6 cams, 4@ 640x480 (mjpeg), 2@ 1280x720 (rtsp) at an average of 10FPS both on a Pi4-4GB (motionEyeOS dev20201026) and production on an I5 M73 Lenovo TFF PC...

You didn't include motion.log, or motioneye.log. I would switch to dev20201026 version of motionEyeOS for PiZero. I don't see anything standing out of the 3 logs you did include.

What was your build environment and which setup instructions did you use? (OS version, etc)

I just checked sever boxen running Ubuntu 20.04 and earlier, all had mkfs.vfat. Checked Debian Bullseye (11) and no installed mkfs.vfat exfat or fat... Must be a new 'feature'. Checking...

I seem to recall discussion about the DebDevs including a new version of exfat support directly in the kernel, will have to check that too, to see if that causes...

Interesting, and I wouldn't be surprised a lot of stuff is missing from a minimal Debian on Pi. Out of curiosity, do you remember the build time?

"I built the image on the raspberry pi platform with a pi zero w as destination." confuse(s)(d) me... I thought you were saying "debian buster, dosfstools wasn't installed by default,...

Clean instance of Debian 10 Server, or something else?

Again, desktop (assuming because you mention x and wm) or server?