I just did some test:
1- This only seems to happen with notes on the iphone, not notes on laptop. Odd no?
No, not odd. An iPhone has a more restricted keyboard, so anything that assists in typing is supposedly welcome. Like the automatic period after a double space, or the comma as a numerical separator. On iPhones those two punctuation marks would normally require a shift to the numerical keyboard, which adds an extra step. On a "regular" keyboard, comma and period are just another direct type key.
