The big problem in your situation is your blood pressure dropped significantly. Maybe it was just a coincidence, maybe not, but you should definitely see a doctor and talk to them about your blood pressure and see what they have to say. Lots of reasons that can happen.

Never used it myself, but my mother has told me when she was much younger she tried pot a few times and stopped because it just put her to sleep, and this was well before the strong strains we have today.

I only ever have seen that happen in RimWorld.

Couple of things it could be:

1. You locked your knees without realizing it, shut down the blood return from your legs, then had a drop in blood pressure due to decreased blood return to your heart causing you to pass out.
2. You took a big hit, expanded your chest, held it, decreased blood flow through your thoracic cavity due to the increased intrathoracic pressure then a blood pressure drop as above.
3. Your vasovagaled yourself somehow (bearing down on a held hit maybe or just due to weed effects) which is increased parasympathetic nervous system tone that drops blood pressure
4. Some weird shit 🤷🏼‍♂️, the body can be odd and changes as we age so maybe you just can’t smoke weed now cause of the earlier mentioned weird shit

I agree with your doc (I’m a family med physician), don’t smoke if all of a sudden you’re passing out.

This happened a few times with friends. They just dropped like a rock and then were pale for a few hours. It’s not uncommon but I would avoid smoking if it keeps happening. Being knocked out for 5-10 minutes is a long time. Passing out is generally considered a medical emergency.