`webp` images are not generated (or copied) to `_processed_` folder using another FAL driver

[Moongazer]

If we include an image from the local fileadmin/ folder, everything works fine and the webp image variants are generated along-side to the equivalent files in _processed_ folder.

But if we include an image file from an AWS S3 bucket through this FAL driver extension, only the common files are generated and copied to the remote _processed_ folder. All the *.webp files are missing. There are no errors thrown and no logs generated.

During debugging we see, that all file variants (incl. webp) are generated inside the var/transient folder. From there it seems they are moved to their final location. Strange is, that only the *.webp files getting lost on their way and never reaching the target folder.

[wazum]

Interesting issue, thanks for reporting. I'll see what I can find out here.