That doesn’t match my experience with AUR at all. Usually it pulls a specific git revision and checks the hash. This also ensures that the build shouldn’t suddenly fail to some extent.

Though it’s entirely possible that it’s not like this for all packages, though I find it kind of counterintuitive since your package manager wouldn’t know when to perform an update in this case.

A diagram of the relevant Hypervisor/VMs/containers + Network information would be helpful.

From where and how are you testing DNS? Did you use dig and specified the nameserver directly?

Zyxel AX7501 has one sfp+ 10G wan and one rj45 10G lan port. Should be around 350$ if you can buy it where you live. I work at an ISP am that’s the device we’re giving to our customers for 10G.

In general I don’t think you’ll get much lower than that even if you build your own router.