Weird combo behavior (not working as expected)

[Lingxi-Li]

Not sure if this is particular to me. Following config should be sufficient to repro on my side.

REWIRE CAPS LSHF CAPS
REWIRE LALT LWIN
REWIRE RSHF LWIN

When I press LALT + CAPS + S, I expect it to trigger WIN + SHF + S which is the shortcut to take a screen clip. Yet, it doesn't work. Weirdly, when I press RSHF + CAPS + S, it works!

I tried debug output. For the combo that does not work, it is like

 [38 0=  LALT >     LWINv ] [M:   4 T:     D:      ]   --  LWINv {LWINv #1}
 [3a 0=  CAPS >     LSHFv ] [M:   5 T:     D:      ]   --  LSHFv {LSHFv #2}
 [38 1=  LALT >     LWIN^ ] [M:   1 T:     D:      ]   --  LWIN^ {LWIN^ #1}
 [38 0=  LALT >     LWINv ] [M:   5 T:     D:      ]   --  LWINv {LWINv #2}
 [38 1=  LALT >     LWIN^ ] [M:   1 T:   4 D:      ]   --  LWIN^ {LWIN^ #1} (tap)
 [3a 1=  CAPS >     LSHF^ ] [M:     T:   4 D:      ]   --  LSHF^ {LSHF^ #0}

Does not make sense and note the missing of S.

For the one that does work, it is like

 [36 0=  RSHF >     LWINv ] [M:   4 T:     D:      ]   --  LWINv {LWINv #1}
 [3a 0=  CAPS >     LSHFv ] [M:   5 T:     D:      ]   --  LSHFv {LSHFv #2}
 [1f 0=                Sv ] [M:   5 T:     D:      ]   --> {Sv #3}
 [1f 1=                S^ ] [M:   5 T:     D:      ]   --> {S^ #2} (tap)
 [36 1=  RSHF >     LWIN^ ] [M:   1 T:     D:      ]   --  LWIN^ {LWIN^ #1}
 [3a 1=  CAPS >     LSHF^ ] [M:     T:     D:      ]   --  LSHF^ {LSHF^ #0}

Maybe, this is an issue with my keyboard? I'm using Microsoft Sculpt Ergonomic Keyboard BTW.

[Lingxi-Li]

Also I have all options turned off.

OPTIONs
off:     debug output for each key event
off:     Z <-> Y
off:     Alt <-> Win for Apple keyboards
off:     Left Control and Win block alpha key mapping ('Ctrl + C is never changed')
off:     Process only the keyboard that sent the first key

[cajhin]

Could possibly be "ghosting or shadowing" (google it, basically not all keyboards can process all combos of keys. Check out n-key rollover if you want to have a capable keyboard).

If it is shadowing, the "hardware issue" is probably that Caps and S are on the same row, and LAlt and S are on the same column. To test the theory, try O instead of S

Update: this is a cool test page from microsoft, try it https://www.microsoft.com/applied-sciences/projects/anti-ghosting-demo

[Lingxi-Li]

Thanks for the info. Looks like it is the root cause.