When I first saw that I posted that I thought it might be new. Someone told me that they thought it only happened when following stop-start traffic up hill. For me it probably was the first time I'd engaged AP in stop-start on a hill (normally I'd use it in traffic that had ground to a halt on highway, so probably only ever used it on-the-flat). Dunno if that applies in your case? (Sounds like this is your regular commute, so it may well be that, unlike my experience, you have used AP in stop-start traffic on that uphill section before)
@WannabeOwner this was a flat freeway (dreaded HW101 in the bay area) - sometimes lovingly called 1 ON 1. So I have had multiple times stopped traffic for 10s of seconds - but never saw this one earlier. I think from other posts, it looks like they have adjusted the trigger time of 30 seconds in the highway, to something like 15 seconds now...