Riddle me this: (Arch) Whenever network connection is lost, NetworkManager freezes for a good 10s. Neither nmcli nor nmtui nor client applications get anything back from it during this time. After that 10s, it detects that the connection was lost and continues normal operation.

Consider this, if you have to ask for help maybe arch linux isn't for you. 😉
Check the Arch Wiki.

that sounds.. weird?

I don't know much about the topic, my first guess would be that the service waits on some answer from the hardware.

I'd assume NetworkManager logs to some extend, I'd check those logs

Half of the network issues I've had in any linux distro has been due to competing network managers. It can be as pain to troubleshoot depending on what all you have installed to troubleshoot it.

@ltlian This is a relatively new Arch install (September) and I don't remember installing anything other than networkmanager.

@halfflat To be pedantic, that's CapitalCase. camelCase doesn't have the initial letter uppercased.

@junon You mean PascalCase?
Never heard of CapitalCase.

@Berkmann18 Yes, thank you. PascalCase*. Got mixed up because if you capitalize every word in a sentence, it's called Capitcal Casing, and is formally defined by e.g. MLA or Perdue.

NetworkManager is indeed a hit or miss especially on Arch-based distros (at least in my experience).
netctl has been more reliable on Arch.

It might not be a problem related to NetworkManager at all.

NetworkManaged uses DBUS and several services for device / connection / service interop.

Could be driver / udev issue, hanging external service / command like VPN, kernel issue, ACPI bug, ....

If you want to find the cuplrit, you should check out the logs. Usually network manager is quite chatty.

dmesg / journalctl / syslog.

It - could - be Network Manager, but if it's exactly 10 seconds it sounds more like NM is waiting for something it doesn't get.

It was an Intel shared bluetooth/wifi card, I noticed that discord starts plinging like crazy the moment I disconnect my headset so I googled for bluetooth/wifi interference and got my answer in 10s from the wiki.