My experience is the same. First I do not know when Dream Drive or Highway Assist will engage. Mostly it gets to Adaptive Cruise Control. On occasions HA engages the car weaves from left line to right line. Sometimes the steering has to be jerked to make it center.I played around with HA on my roundtrip drive up to Chapel Hill to pick my son up from UNC. On both legs, HA started out as "merge left". I would turn it on and the car would just drift to the left, over the line and had to have some intervention before I hit the wall or ran off the road. Later on in the drive, I tried it again and it appeared to do what it was designed to do. It just isn't consistent enough to be trusted and is downright dangerous. Not surprisingly, HA acts much like the entertainment system, sometimes it works, sometimes not so much.
No more HA for me.
I hope Lucid fixes this annoyance. I own a Tesla. I find that self driving easier. May be in course of time I will get used to Lucid.
RKW