Hi @stdcerr & @cpu_12 and welcome to the balena forums!
I maintain the balena-etcher package in the AUR (https://aur.archlinux.org/packages/balena-etcher/) and have just pushed a downgrade to pin the package to 1.5.60 for now, which I’ve confirmed to be working. I need to investigate what’s changed a bit further, and hope to get to that by the end of this week (support for this package is “unofficial” and I do my best to keep up!). If you require the latest and greatest balenaEtcher, I recommend using the etcher-bin package: https://aur.archlinux.org/packages/etcher-bin/ at least until this issue is resolved.
Please let me know if you’re still having issues, otherwise you should be forced to downgrade at your next update.