Run dconf-editor and search for "mouse" entries. Try to change some options like "acceleration time" or "mouse tracking mode".
Try Elementary Tweaks, as described here (https://itsfoss.com/install-elementary-tweaks-in-elementary-os-freya-luna/). It will appear in Settings panel.
Looks like it's related to a keyboard shortcut associated with this combination. Go to System Settings -> Keyboard. The tabs Layout and Shortcuts have all configurations for it. Since I'm using ...
Try this: Wingpanel Nightlight Indicator https://github.com/elementary/wingpanel-indicator-nightlight