Mousebutton 4/5 weirdly assigned?

[quepro]

Hi, so i just recently started playing factorio, and I dont have any custom keybinds, yet. So i want to assign them to shortcut 1&2, but MB4/5 keep opening the research window or map for no reason, completly random. In the setting i cant find any bindings to MB 4 and 5.
Please if anyone is familiar with this issue, help me out

[Loewchen]

They will by default open and traverse the last opened GUI as shown in Controls.