I130 Online Filing Warning Message

I am US citizen thru naturalization,  try to file I130 online for my brother. When I select Brother/Sister for the beneficiary, there is warning message.
 
You may not meet the eligibility requirement for your petition
If you are petitioning for your brother or sister, you must be a U.S. citizen at the time of your petition.

I double checked my naturalization date which is well before year 2024. Anyone ran into this? If I select Parent, it has the same warning. If I select Spouse, the warning message is gone. Not sure if this warning message would delay process.

Thank you!