I recently moved from a two-monitor setup to a three-monitor one. Previously, desktop alerts worked exactly as desired: they would appear on the bottom-right of the primary monitor, above the taskbar. However, since adding the third monitor, desktop alerts have been misbehaving. By default, they appear on the secondary monitor, way above the taskbar. It's not possible to drag it straight down to the primary monitor. It's possible to drag the alert to the side and kind of sneak it onto the primary monitor, but the moment the alert is fully contained by the primary monitor, the alert gets kicked back to the secondary monitor.
I have attached an animation of me trying to drag the alert from its default/initial position on the secondary monitory, to the tertiary monitor, and it getting kicked back up after falling onto the primary monitor.
I'd be interested to know if anyone else has run into this issue and has a solution.