Do you have a link to your gallery first though? So I can see the real render paths to your images? Render request links are mostly the same, except now the cached element will be stored in the exact path as requests (instead of being redirected to PHP, which then serves the cached file from another location). Before checking the CDN version, shouldn't we be checking the actual output of these requests on server first? I do see TWO issues, and I'm guessing the first one is the problem:
1. w270 is not an "allowed" request width in X3 any more. If any request width is available, it means "bad people" or bad bots could hammer your server with requests w1,w2,w3...w999 (and so on) for all your images, creating insane processing demands on your server. Please go to Settings > Advanced > Image Resizer > "Allowed request widths", and click the [?] help icon for more info. You can add your own custom request width there, for example
270. See what happens when you request w270 on our demo for example:
https://demo.photo.gallery/render/w270/ ... apples.jpg
Use a pre-assigned allowed width like
200 or
320 (it doesn't matter if images scale down slightly in your forum). Or if you must, just assign "270" into "allowed request widths" setting.
2. This is not related to the problem, but you can remove
q100 from the request width. All requests will inherit the quality that you have in Settings > Advanced > image resizer > quality. If you allow different quality, it means someone could create 100 variations of each of your images. Besides, what's the point of having this in the request, and what's the point of setting it to 100? Default 85 is already generously high.