Welcome to the internet. You will be probed. Just as your immune system, or rather your body, is being probed.

Just don’t run broken software. The attackers will not be able to exploit you then. If they have zero day exploits, the WAF will most of the time not save you since they are often pretty easy to circumvent. WAFs are only effective against old and shitty exploits that should be patched anyways since ages.

Attack surface is made of the amount of code that is running when an attacker speaks to your machine. Imagine a freshly installed GNU/Linux distro with no services. The attack surface is minimal. All packages sent to your machine will only ever be touched by relatively limited parts of the linux TCP/IP stack and NIC driver. If you now run a web server, the package coes through the NIC driver, TCP/IP stack and web server. The surface is increased. Each of these parts of your machine’s code could have bugs. The more code your attacker’s packet runs through, the more opportunity to make your machine do things you don’t like.

If you want your machine to do what you like but not what random attackers like, it is therefore mandatory to have the least amount of attack surface, not adding code in contact with your attacker like a WAF or “antivirus”. Both these kind of softwares will inspect the packages coming in an take decisions (potentially bad ones) based on the content.

WAFs will mostly not help you since on a well configured and patched system, little known bugs are exposed. They might help you occasionally but usually patching the system is more effective. Of you want this to happen automatically, it’s entirely possible. Most os’s allow automatic unattended upgrades.

Wafs don’t make you safer but create unnecessary attack surface. Just keep your machine and services up to date.

The fuzzy skin came out very nicely!

Most probably PA. You should try adjusting it while printing using some g-code console. This way you get immediate feedback. What they often don’t tell you is that pressure advance is not something you can calibrate once and forget, it’s dependent on material, temperature, nozzle diameter and also a lot on feed rate and extrusion rate.

The need for PA and precise tuning is more pronounced the higher changes in extrusion rate you have eg, you print very fast or with wide or high layers.

Just play around with it a bit and I’m sure that you’ll find a better value after some layers.

There are even macros that try to remove the feed rate dependency by effectively replacing every g-code that adjusts feed-rate by a combination of the original g-code pre-ceded by an adjustment of PA. I haven’t tried them out yet though.

What’s weird is the differences of the effect between the layers. Is the every layer the same or is the path different for different layers? Maybe post some images of the inside of the model.