When you assign icons to folders or files, they disappear. The iconize plugin.
Surprisingly, sometimes it saves.
I also tried to insert from the iconic and inons plugins - it didn’t help.
screenshot 1 - showing what happened after 5 attempts
screenshot 2 - I show which files it flies on
screenshot 3 - after 20+ closures, they did not fly off
Moreover, the icons of obsidian itself are not saved either.
First, did you try to ask for help on the website hosting the “iconize” plugin? Did you check if this plugin is still under active development?
The developers of Obsidian (here, in this forum) aren’t responsible of outdated plugins and can’t help.
Some authors are busy or abandoned their projects and won’t answer anymore. Then, you may ask here as a last resort.
Unless the plugin author uses this forum as well and casually stumbles on your post, (which isn’t even tagged as “bug”), you won’t hear any news.