We found our site users can join products without admins approval since 2024/3/25.
It's an abnormal operation and It never happened on out site before.
After we check our settings, we found the "Admin approval" is unchecked

However, we didn't modify this setting. So we want to check if it's a policy change from Atlassian. It impacts our user managenment and probably make us pay more for those users.
For now, we just checked "Admin approval" to stop user access product as we expected.
reference: Control how users get access to products | Atlassian Support