As mentioned on Discord the window close sound is popping up all the time when ppl leave or join the group. You mentioned something about the Artifact Scan and that I should open a ticket. Here you go. ;)

From https://mods.curse.com/addons/wow/aethysrotation?comment=18

Aisenfaire
Posted Mar 9, 2017
Hi,
Something weird: whenever I have this addon enabled, I keep randomly hearing the sound of a UI window being closed (like for example if you closed the artifact window). It doesn't happen in combat (it's possible it just got drowned out by combat noise but I don't think so), but out of combat it keeps randomly playing with some frequency.
Also, the talent window immediately closes after I change 1 talent (while this addon is enabled).