missing layers...

Hi! I just recently got my Ender 3 v3 KE. Everything’s been going well so far, but I’m having a problem with missing layers at 3.5cm and 4.5cm heights…
I’ve adjusted the flow rate up and down… going up was better, but far from perfect…
All the screws are tight. The Z-axis is straight, too.

Any suggestions on what else I could do?

The pictures with the broken ear are at low flow, and the others are at higher flow.

I use Creality Hyper PLA.

Thanks and best regards,
Marcus