ok, I fixed it again! What I did was to select the 519 camera with the mini model, then as there was no image I selected the 5mp arducam and rebooted. Then I re-selected the 519 and rebooted. Once it came up again the image was there on the scan page. I did try this when it wasn't working, but may not have chosen the 5mp that time. The /boot/config.txt isn't the same between the version that didn't work and the one that works, despite the web page config being the same.

I initially had problems getting openscan to recognise the 16mp camera on a Pi2b, but after messing around a bit I managed to get it working well yesterday, however for some reason it no longer recognises the it today. The only thing that I did in between was to power off & swap the SD card for one that had a bare bullseye install that I then set up with the camera. Got that working quickly, swapped the original openscan sd card back in to carry on with testing so I could decide whether to go with the classic or mini build, but openscan no longer sees the camera. I've reburnt the openscan sd card with the same image (22-04-20) a few times and it just doesn't display an image, just a broken image icon. I've edited the /boot/config.txt file to make sure it has the right dtoverlays enabled, but it then locks me out from ssh, despite being enabled on the web page. The image or broken icon aren't even there on the scan page once I've done this, so I reburn and start from the beginning. (btw: I've used the stable version rather than beta.) The bare sd card I set up still works so the camera is ok, and I'm now at a loss on which way to go. Any help you can provide would be appreciated, thanks.