Didn't see the lights personally but this is hitting close to home because I had something similar happen on the M6 a few years back. Pulled in at a services near Stoke and genuinely could not account for about 40 minutes. Just sat in the car park with no memory of arriving there. My phone showed I'd been stationary for nearly an hour.
What gets me with these highway cases is how often they follow the same pattern - lights, confusion, then this weird calm feeling right after. Almost like your brain is buffering or something.
What direction were the lights coming from? And did anyone else in the car experience the same gap, or was it just you? That detail matters a lot I reckon. Would love to hear more about what you do remember from just before it happened.