alt-tab + external monitor

Hi,

when I use a secondary (VGA) monitor I often have distinct resolutions.
Eg: eDP = 1366x768, VGA = 1920x1080
In such a configuration Fluxbox' Alt-Tab behavior starts to be "inconsistent":
Some windows stop being focusables by keybinding (mouse still works)

Here is my config:
> Mod1          Tab        :NextGroup (workspace=[current]) (head=[mouse])
> Mod1          Shift Tab  :PrevGroup (workspace=[current]) (head=[mouse])

(It's fluxbox 1.3.5, but I "always" experienced this issue)
Is it a known issue, am I overlooking something?


Thank you

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