Make sure that you always change your birthday, even if it’s a wrong one, to 13 years of age or older to be able to change it at a later date. How to change your age on Roblox account (PC desktop)?

In addition to confirming ages for individual accounts, Roblox also said it plans to adopt new systems that will limit ...

That indicates that that user is also using voice chat. Note that even if your account is already age-verified, you'll have to manually enable Spatial Voice Chat, as it is disabled by default.