Disable resizing of specific tabset

[AregShahbazian]

I wanna disable the horizontal splitter between my tabset X and its neighbor.

Setting pointer-events: none; to the specific splitter works. However, there are multiple horizontal splitters in my layout, and the one I need is somewhere in between. Selecting it with .flexlayout__splitter_horz is not possible.

Is there a tabset attribute that I'm missing? Or an easier way?