Saw that story back in 2014 and it was very real, the beard got knocked off during some cleaning work at the museum. The glue failed and it popped right off the chin, there's actual video of it sitting there on the mask. I get why people thought it was fake because it sounded like a joke, a 3,000 year old beard falling off like a cheap toy. But the museum had to glue it back on with beeswax, and they talked about it openly. So yeah, it really happened, it just got buried under all the other weird news that year.