Link got broken: shows different icon

#1 /ios/16/000000/twitter.png

These icons now look like one geoposition mark (instead of facebook), another one like a glass of wine (thankfully nothing more provocative) - instead of twitter, and only an Instagram icon remained. So every our letter now looks like an invitation to a party with coordinates and a prearranged photoreport.

The thin is that id to change size to any number else except of 16 it looks wright again. we are ok to change the size but as I’ve told all our previous letters look bad now. Is there something we can do?