E-File Rejected because Son filed as a Non-Dependent

My son is 24.  He has a learning disability and is enrolled in a school for people with disabilities.  I pay his rent.  The state pays for the school.  I pay his gas and $100/week for expenses.  He does earn some money by delivering for DoorDash.

He filed his taxes, and he did not file as a Dependent.  When I filed, it was declined because I had listed him Dependent.  I took him off my taxes.  That cost us over $2000.  I submitted my taxes and it was accepted.

Now, my wife and I want to know what we can do to fix this and get his Dependent status back.

Thank you!