Hey noobster,

In order to delete the image, you have to:

1) Edit the post that has the thumbnail block.
2) Click the desired image.
3) Click the remove block button on top of the composer.

You can refer the attached image for reference.

thx i understand. maybe a better name for this action would be better "remove block image" or something else. i thought it means to remove the whole block.

Yeah, it is kinda misleading. I'll see what I can do to affect the change to our developers, but you can suggest it on Voices

Glad I can help with your issue