@jannew , you seem quite forum/posting savvy to me. I do wish you could get in sooner with his doctor, but that’s not in your control. Not sure where you are located. Some places are very booked up.

With my dad, he was seeing his PCP all along, so he saw the gradual progression and noted it in his file. Fairly early he offered the standard dementia pills, which my dad took. Started with one then added the other later. Really helped. Daddy was on them for years. He had slow progression and never got to a level you might expect after so long. At some point, daddy got an MRI. All it showed was that he hadn’t had strokes, no injuries, no fluid, no tumors. He did word circle games for a long time. But, Alzheimer’s did eventually become fatal.

I got my cousin in with a PCP in about 2 weeks. I explained it was urgent! She was having a lot of symptoms mental and physical. Bizarre behavior. Her primary had retired. I handed the doctor a letter describing the symptoms. She gave exam, took blood and gave Mini Mental Evaluation. She then diagnosed her with severe vascular dementia and referred her to a neurologist at my request. She also ordered an MRI so we would have it ready for the neurologist. We got the MRI in about a week, then saw the neurologist in about a week after that. The neurologist looked at her records, MRI and did office evaluation. He told us it was vascular dementia.
That provides a time line from my experiences. I’m sure it varies by area.