ID 416469 - The interpolation of animation on OFX enum knobs is linear by default, rather than constant

Problem summary

The interpolation of animation on OFX enum knobs is linear by default, rather than constant.

Steps to reproduce

1) Open Nuke

2) Create a F_Regrain node

3) Set a key on the Preset Stock knob at frame 1. You can keep the default value of the knob (FUJIF250Under 2K) at this point. 

4) Set a second key on the Preset Stock at frame 20. You also need to change the value of knob, for example Kodak200T 2K.

5) Playback the animation and notice that between frames 10-20 FUJIF500 2K  is set as the knob value.

Expected behaviour
The interpolation should be constant, rather than linear.

In the steps above, the knob value should be FUJIF250Under 2K from frame 1 to frame 19, then change to Kodak200T 2K on frame 20.

Actual behaviour
Interpolation of animation on OFX enum knobs is linear, rather than constant.

Workaround
You can set the interpolation to constant in the Curve Editor (select the points on the curve > press the k key).

Reproduced by support

This bug has been reproduced in:
Nuke 12.0v3 - Windows 10 - macOS 10.14 (Mojave) - Linux CentOS 7 

Nuke 12.0v1 - Windows 10

Nuke 11.3v1 - Windows 10

Nuke 11.2v1 - Windows 10

Nuke 11.1v1 - Windows 10

Nuke 11.0v1 - Windows 10

Nuke 10.5v1 - WIndows 10

Nuke 10.0v1 - WIndows 10

Nuke 9.0v1 - Windows 10

Nuke 8.0v1 - Windows 10

Earliest version tested
Nuke 8.0v1
- This issue appears to be in all versions of the product