US Immigration from Singapore

My I-751 has been pending there since June 2020 My N-400 pending there since June 2021

I mean logically they could kill two apps with one combo interview & clear their deck. Why aren't they doing that? What exactly did we pay $1,400 for? I understand every case is different but why are cases filed after me in Dallas getting interviewed before me? USCIS told me they are waiting for Dallas office to schedule the interview! is it the case of a lazy officer?

My wife attended her citizenship interview last week and passed her tests. She was informed her citizenship can't be approved at that time because her 10 year green card application was still pending. The day after her interview her 10 year green card application was approved. She received a notice of action saying that her 10 year green card application was approved, but that she would not receive a new green card because her citizenship was already approved. When we check her account online and when we call the USCIS phone number her citizenship status does not say approved. They both say her interview was scheduled. Our concern is that she currently has no green card. They kept her 2 year green card at the citizenship interview and the NOA for the 10 year green card says they will not send her one. We haven't received any NOA saying her citizenship is approved and the USCIS website and phone number both say that there is no approval yet. We have no idea what is going on. Has anyone dealt with a similar situation?

My aged if parents want to visit me and they need documents to prove they won t overstay. They are in their early 70s and 80s so won t have any paperwork to claim they are working. I also understand that a letter of invitation is not necessary. Should I give them copies of my marriage certificate and geeen card? Should I also write a statement that I am

sponsoring their stay?

I filed I-751 in June 2020. In April 2021 I got new status message that case ready to schedule for interview as of April 2021. Today that message got updated with a new date of March 2022. Any one had similar experience?

I went to USCIS office on Feb 11 to file my fingerprints, but now it's still not updated yet. I know sometimes the website can update to "Fingerprints are taken" 1 day after the collection day, just curious what is the common timeline here.