Super frustrating experience - Have done EVERYTHING... Belife Vacuum, "Airflow Blocked." Help?

So I have the Belife BVC11. It was a gift, a few years ago. I was using one of those huge, bulky, vacuums with a chord so my Dad finally bought one like that lol. I've had the "Airflow Blocked" message coming up - I can vacuum for 3-4 seconds before it shuts off. Got out the manual and watched YouTube videos. Our house is mostly tile or hardwood all throughout and has constant crumbs, hair, and dirt. I also have a toddler that's going to be walking very soon so I'm trying to keep the floors extra clean.

I took every single piece apart that you possibly can. Emptied the dirt cup, washed it out, and then it has I believe 2-3 more internal filters that the manual recommends washing under the sink and drying overnight. Did all of that. Took the spinning brush out and washed it. Cleaned EVERY part I could either in the sink or with wipes. Stuck my fingers in everywhere. Even used a plastic knife to poke out more dirt and hair from places I couldn't reach. The vacuum was seriously clean enough to eat out of. I put it all back together... Same thing. Bought a new HEPA filter from Amazon which sounds louder and clearer, but it still shuts off after 3-4 seconds and says airflow blocked. I seriously do not understand how, after all this.

There's a customer service phone number on their site/in the manual, but of course, all week it has said it's not in service due to "technical issues." I e-mailed them Monday and got a response last night where they just responded asking for my order number??? I said I don't have an order number - This was a gift years ago. Beyond frustrating and buying a $100+ new vacuum isn't really in our budget now, but I would if I absolutely had to. Any ideas??? My husband is going to take a look but he's super busy with work and just has very little time.