Generated theme causes a transparent line below the address bar in Chrome

[krims0n32]

As you can see in the image there is an annoying transparent line below the address bar. I've tried Oomox and Materia as base but both have this issue. If I switch to any other GTK theme, the problem goes away.

These are the versions and plugins I use:

themix-export-spotify-git 1.2.8-1
themix-full-git 1.15.1-1
themix-gui-git 1.15.1.r26.gd2fcbb56-1
themix-icons-archdroid-git 1.0.3.r0.gb90779de4-1
themix-icons-gnome-colors-git 5.5.6.r0.gd2cb7eb-2
themix-icons-numix-git 22.08.16.r1.gb5001d962.e6197dd14-1
themix-icons-papirus-git 20220910.r12.g11e75c8a6c-2
themix-icons-suru-plus-aspromauros-git 3.0.r0.gd43a8ec4-2
themix-icons-suru-plus-git 30.0.r2.g9bd895f32-2
themix-import-images-git 1.15.1.r26.gd2fcbb56-1
themix-plugin-base16-git 1.5.3-1
themix-theme-materia-git 20210322.r50.gaf63425f-1
themix-theme-oomox-git 1.12.4-1

[Addisonbean]

I'm also having this issue with all the themes I've tried in the Brave browser as well.

[actionless]

firefox and google chrome not really using gtk engine in conventional way as any other application - but instead it initiates stylecontext and just grabbing some random (didn't saw them publicly documented except for in multi-thousand SLOC source file of code which does that) values from the theme.

so without knowing which exactly of theme values causing that problem i can't do much, however in "qt" theme (which also don't using qt engine directly but grabbing theme values separately in the same way) that problem is not happening

[actionless]

(and unlike in apps which using gtk engine conventionally - there is no way to use gtk debugger for observing which theme keys affecting which types of the interface)