On a large window, if a Pane is linked to another one which is on an other axis than the window, its texture is no longer connected to any other Pane :

Note : I modified the CTP so the Panes have no longer the issue referenced in #30 and here, but please don't tell me that's why I have this issue : it was already there before and the border is on the non-corner Panes

Minecraft : 1.12.2
CTM : 0.3.3.22
CTP : 1.2 for MC 1.12 (customized)

This is intended behavior when connect_inside is false (the default)

Oh... my bad... Thanks, I close this issue then
I tried to turn it true but it doesn't change anything on the moment. I guessed it needed a restart.
So did I, but it caused this config to turn back to false, and I'm stuck with the disconnexion.
The other config (disableCTM) has the same problem.
I modified configs of other mods and they didn't do this

Not the config, it's a flag in the texture data. https://github.com/Chisel-Team/ConnectedTexturesMod/wiki/Extra-Data#ignoring-states-and-obscured-faces

Got it, thanks !
I still think the config should be able do it for us, but at least for now, I can patch it by myself.
I'll also try to get rid of the horizontal stripes between the Panes while I'm on it.