Passport stamps and i94 issue



I just noticed that when I drove to Canada, the US Officer did not put a stamp in my passport, but on the Canadian side they did.
Now I am about to send my AoS package to USCIS and I just realized above issue. Furthermore, the i-94 most recent date of entry is not showing my Canada trip date, but the previous date when I flew in to US. When I click on the travel history though, I can see that I was in Canada, so I was inspected but without a physical stamp and most recent date of entry does not reflect this trip.

So my question is, does most recent date of entry not get updated when you cross the border by car? Because the most recent date I entered USA was the date when I drove to Canada and came back.
I'm also not sure if I should put on my i-485 form the day I flew in to USA or the most recent trip I did to Canada and came back.

Please let me know what you think...