Fabric Loader: 0.16.9
Fabric API: 0.111.0+1.21.4
Minecraft: 1.21.4

Actual

When the "high contrast block outlines" accessibility option is enabled and fabric api installed, only the blue line is visible

Expected

There should be a blue line as well as a thicker black line, like there is in vanilla and fabric loader (without fabric api)

Additional

As seen in the following screenshot, the black line is still visible if the thickness of the blue line is decreased