The hashtag 10yearchallenge is very trendy now, but the use of the compond adjective (10-year) makes it look like it's a challenge that spanned 10 years, however, it's the name of the challenge not an adjective describing it.

I'm very confused about the use of this form and would ask your advice if it's the correct way to say it, and why.

Thank you


It means that the challenge includes a span of 10 years, not that the challenge takes place over 10 years.