Syntax for reducing image inside layer not working

I own this map Duplicata da Mangiare in Slovenia - uMap

I just noticed that the syntax for reducing the size of an image within the layer no longer works. Is this a temporary server-side issue or has the syntax changed?

The syntax I used is the following: {{https://…|40}}

I noticed that if I create a new map, this problem doesn’t exist. I therefore thought that there is a bug related to choosing the link target _self, instead of _new. Which by the way is no longer available now.