US Immigration from Dominican Republic

Hello, how are you, we are F2A, on January 23, it was our consular appointment and we were denied under section 221g, my mother was missing a birth certificate and they asked me to make an I-864 exclusively for me.

There it is, the problem lies is when uploading the documents, in my mother's profile, I was able to upload upload and submit the documents correctly, but when it comes to uploading the I-864 in the profile of the guarantor that I fill for me it only leaves me Uploaded it but I can't submitted it idk why, it doesn't let me and I have tried it on many devices, different internet, places and I have checked that it does not weigh more than 2megas, the document is scanned correctly, it does not have a password the pdf and everything is fine I don't know why..

Has anyone happened to you the same thing that can you help me, please?

It should be noted that I have already sent my mother's document by mail to the embassy, only my document is missing. Although I wrote to support, they haven't given me an answer.