borderless window mode mouse click bug

i don’t frequent these forums - apologies if this is not the right place.

i’ve had a devil of a time trying to troubleshoot a missing mouse click and keyboard stroke bug, and tracked it down to an unreal engine issue that spans multiple games, in borderless window mode. periodically, mouse clicks will get missed, whether its left, right, thumb… and also keyboard strokes. it feels like it could be focus loss related, but i really don’t know about that.

originally, i ruled out the application because it was happening across 3 (bloodhunt, fault, overprime), but after swapping kb and mouse repeatedly, i finally swapped the whole computer, and still had it - shortly after i figured out it was application side in all cases. changing to native fullscreen resolved the issue.

i have to imagine something about my setup contributes - or else tons of folks would have that. my display is a 3440x1440 widescreen, and i used that during this entire process (that is the only common hardware i had between the two machines, maybe outside an ethernet cable or something). using that, i get borderless window mode as a default. some of these games periodically reset my graphics defaults, which i think contributes, as i would normally be switching to fullscreen native just as a standard practice.

my monitor is an alienware (dell) AW3418DW, and i run windows 10 on both PCs. i can reproduce this reliably across multiple machines and can correct it immediately by changing to native fullscreen. overprime was a closed beta, so i can’t touch that, but the latest versions of bloodhunt and fault, this happens. lowering my sens made this dramatically worse over time.

is this a known issue? can i provide logs or something? thanks!

I think there’s something wrong when DPI is set to something larger than 100% and the mouse cursor (hidden or not) reaching the edges of the window. I can reliably reproduce mouse clicks not registering at the edges when my DPI is set to 125%.