Doorbell alerts while not at home

I recently received an alert that someone was at our door but I was away from the house. I THOUGHT that the Video Doorbell allowed me to communicate to whomever it was but both the speaker and the listening icons were greyed out and in addition to NOT being able to SEE who was at the door, I wasn't able to hear OR speak to them either! Being able to see and hear/speak to the person/s at my door REMOTELY was a VERY important feature that propelled me to buy this product and, when I needed those features to work, they didn't! I should mention that my Mom has Alzheimer's so, and although I rarely leave the house, it's extremely important that I have these features working properly when I HAVE to. Is there something in the set-up that I need to do/change? WHY aren't they working.... any clues? Thanks, in advance, for ANY help anyone might have for me!!!