XF 1.5 Images proxying is not working correctly

[ESXi]

That is not for all images, but some have:

When I click Edit - images are shown there.

Could you point me on some misconfiguration of my forum?

 

[Mike]

Please try the "test image proxy" option under tools in the control panel. What does it report for one of the failing URLs? (What is one of the URLs?)

 

[ESXi]

Please try the "test image proxy" option under tools in the control panel. What does it report for one of the failing URLs? (What is one of the URLs?)

Thanks! I checked and found that:
doesn't work:
https://qph.ec.quoracdn.net/main-qimg-c9b97821464ae2d8b21049cf74e11a40.webp
works:
https://qph.ec.quoracdn.net/main-qimg-ecd5a0523ad62d7b0f7b16f919ef0370

I removed ".webp" from the first link and it works!
But why it copy-pasted differently?

 

[Mike]

That's likely the image that was offered to the browser. It's a format that isn't universally supported (and the image proxy doesn't support it as a known format).

It's not really easy to solve, as it's actually the image that the user saw, but the image would be variable depending on browser capabilities.