macOS 26 does not render GraphicsContext Gradients correctly

[neofelis2X]

Hi, I updated to the new macOS version and it seems Apple is breaking things again.

Operating system: macOS Tahoe 26.2
wxPython version & source: 4.2.4, pypi
Python version & source: 3.12.8, stock

Description of the problem:
Gradients that are created by gc.CreateLinearGradientBrush or gc.CreateRadialGradientBrush are rendered as a solid colour.
I noticed this in our software, but the wxPython demo shows the same behaviour.

Code Example (click to expand)

  # draw gauge background
  gstops = wx.GraphicsGradientStops()
  gstops.SetStartColour(cold)
  gstops.SetEndColour(hot)
  gs = wx.GraphicsGradientStop(medium, x1 / (xE - x0))
  gstops.Add(gs)
  brush = gc.CreateLinearGradientBrush(x0, y0, xE, yE, gstops)
  gc.SetBrush(brush)
  gc.DrawRoundedRectangle(x0, y0, xE, yE, 3)

Would be interesting to know if more people experience this problem.

[neofelis2X]

Update: This happens with python 3.12. Python 3.13 and 3.14 render the gradients correctly.
The software used to support python 3.11 at the lower end, until now...