Have you checked that the debris door isn’t jammed closed? It’s the little door that closes when you have the stick vac pointed down. It’s just inside the nose opening. You might need to take the bin off to see it properly. 

Badly referenced location on an online image - hopefully this helps you locate it. 
 

Kirby.

Thanks! I removed the bin and didn’t see anything blocking the airflow bit I’ll look again! 

I’m not sure if you’ve seen their YouTube video yet?

Might show you something that could have been missed. 

Pulsing usually means a blockage. If could also be an issue with the filter. If the video doesn’t help fix it, maybe this post will: 

Jay.

Thank you! I had already completed those step. I was actually able to get the pulsing to stop after removing both of the filters, so now I’m thinking maybe they were still wet? Or I may need to replace the top filter. I’ve rewashed and am letting them dry for several days and will try again once I place them back in the machine.