We waited for the 90 days prior window to open. We carefully prepared and sent the removal of conditions packet before travelling to immigrant's home country for a wedding celebration (3 years of waiting to finally hold a wedding in her country). By some twisted fate, the USCIS decided to act with lightning speed and schedule an appointment in the short term. I got back and received the mail 2 days after the appointment had passed. Since then, we have called 3 times, I have uploaded a letter as additional evidence to our case, and we have gotten absolutely nowhere, all under constant threat of our application being discarded.
The first call, we were given a reference number and told to wait for the rescheduling. It never happened. Our second call, the gal was a little more helpful. Unfortunately, a few days lot we got an email saying we could reschedule online, as if this were a solution. It' wasn't, of course, as we cannot reschedule online. We called back to try again, since the canned solution does us no good, and guess what? We can't make another request for an additional 30 days. I guess it wouldn't be a "visa journey" without some mind-numbing incompetence strewn along the way.
For those interested, this link covers important details about rescheduling, as well as good cause. If you want to go a step further, you can even find a pdf of the policy manual explaining what is considered good cause:
https://www.uscis.gov/newsroom/news-releases/uscis-launches-online-rescheduling-of-biometrics-appointments
At this point we are wondering if we can just get to the time where we can apply for citizenship since that is easier than trying to re-schedule biometrics.