This is pretty new! Google asks you to share how long you've been in business in the GMB dashboard.
Tim Colling shared a post with Local Search Pros
New GMB Question "When did your business first open?"
This is the first time I remember seeing this question for a client's GMB information. Is it new?
View post, then come back here to discuss it.
In that discussion Joy says it's borked.
Have you seen it yet? Does it work now?