[arch-general] External monitors are no longer detected (Intel graphics)

Hi, I'm using a Thinkpad T450s with Intel graphics. Yesterday, I could no longer connect external monitors via miniDP. They were not detected at all, either by xrandr in i3 or by sway (wayland). I didn't have time to dig out a VGA cable and try that, so I cannot rule out physical damage yet - I did try 2 monitors with different cables, both of which work with my wife's Thinkpad. Since wayland doesn't make a difference, I'm thinking maybe something broke with the (my?) drivers? Is there any other possibility apart from physical damage, and what do I try next? Cheers, Bennett