Halp
I would call it under extrusion. Dry your filament if you haven’t and print some XYZ cubes at different temperatures to see if you need to print hotter to let the extrusion keep up. Simply printing slower could also help but that is also slower.
First some establing questions:
What are your settings?
What machine?
What kind of filament?
It looks like under extrusion but to properly diagnose it it will help to know the other info.
-Sovol Sv06 with upgraded cooling to a dual duct 5015
-hatchbox grey PLA
-settings are off the top of my head because the machine is in my office, but hotend 185 bed 70, ret dist .4, raft.
-otherwise the prints are coming out in great quality, no stringing. Did a temp tower and overhang before to dial in the new PLA.
-the machine sat turned off for a good month or so before swapping in the new PLA, so I might swap a new nozzle on and see if it improves.
This one has happened to me a lot. Firstly I had to up the temp on my hot end . I started off printing at 195c but realised the room was quite cool. I’ve ended up with my hot end at 215c and it works brilliantly. Secondly, whenever I get a print like this now I suspect a clogged or damaged nozzle. You could unclog it but a replacement is very cheap and easy to install.
I forgot to mention - I once could not diagnose a problem like this on my work printer. Turns out the extruded had a small crack and thus would not feed in the filament at the correct speed