ID 431386 - Direct Light samples option of Render settings cause firefly noise in specular shading

Problem summary
Direct Light samples option inside Render settings cause firefly noise in specular shading

Customer reported version
modo.14.0v1

Customer reported platform
windows10

Steps to reproduce

1) Download and open the attached scene file.
2) Go to the Shader Tree and select the Render item.
3) Inside the Render items, properties select the Settings tab and set Direct Light samples to 64 and notice the noise it produces.

4) Now change it back to 0 and notice the noise isn't present.

Expected behaviour
It should produce a clean result.

Actual behaviour
The firefly noise is present.

Workaround
Unknown.

Reproduced by support

This bug has been reproduced in:

14.0v1 - Windows 10

13.2v1 - Windows 10

13.1v1 - Windows 10

13.0v1 - Windows 10

12.2v2 - Windows 10

12.1v2 - Windows 10

12.0v1 - Windows 10

11.2v3 - Windows 10

11.1v1 - Windows 10

11.0v3 - Windows 10

11.0v1 - Windows 10

Earliest version tested

11.0v1 - This feature did not exist before this version.