Reslice Cursor LineSource appearing dark in certain older iOS devices

Hi,
I am using the VTK JS version 14.15.5, And I am running the “ResliceCursor” example on three different iOS devices iPhone SE2, iPad(6thGen) and iPad Air(4thGen).

While running the example on iPhone SE2 and iPad Air(4thGen), all the lineSources used in the example appears normal

But in the iPad (6thGen) the vertical lineSources appears as a black line or shadow (Image Attached)

I could compare that the iPhone SE2 and iPad Air(4thGen) were launched in the last one and a half year, but iPad (6th Gen) was launched on2018

And when I try to the example from the VTK latest release V18.1.2, I could not find the working “ResliceCursor” example.

Kindly let me know how I can fix the issue of the Black line in older iOS devices.

iPad(6thGen)