[SOLVED] Wysiwyg some image are not displayed

Hello,

I have the following problem, I can upload .tiff files and view and edit them under Assets (Imagick is installed).

But when I drag it into the wysiwyg editor, it is first displayed with the url /admin/asset/get-image-thumbnail… but after saving it becomes a /IMAGE_NAME.
After that the image is not displayed anymore, not even a dummy image.

I have tested this on the demo environment where the images are converted to webp.

My question is now what do I have to do to generate a thumbnail of tiff when I call /admin/asset/get-image-thumbnail.

Thanks a lot

Update
I’ve solved it this way:
At insertHtml (CK4Editor) event I check for images and replace them with a thumbnail which is returned from the controller.
This way I have also inserted default captions, too.