Images with square srcset don't load on iOS. The original image is shown in stead

I’m using a thumbs file with predefined srcsets. So far it has worked like a charm but I’ve run in to an issue.
I am using a square image srcset, like so: srcset="<?= $image->srcset('square') ?>". This beautifully works in my browser and I can see al the img sources (they are all square). However in iOs the original image is shown.

I don’t understand why this is happening! It got me wondering if it’s a fault in the system. Or I have to provide a fallback.

Thanks in advance for the response!

What file formats are you using? which iOS / Phone is it? i think you are getting this because none of the srcsets you have match the size of the iphone screen. An iphone 12 for example is 2532px x 1170px so i think its falling back to the original image because its the best version of the image one for the size of the screen.

It is iOs version 14.6 and the file format is jpeg. Here is my srcset setup:


You’re right about the fallback image, that is the original image indeed. I misunderstood that :).