OGRECave/ogre

Hi, I'm having problems with updating a compute program named constant (v. 1.12.5). The value gets updated the first time but not after that. I have verified this with Nvidia Nsight.
What I'm doing is that I'm trying to update a particle buffer in a compute shader. The particles have an age and the age is increased every frame with the time since the last frame which is passed to the shader as an uniform.
Here is how I create my compute compositor:

// Creating a compute & render compositor
auto compositor = Ogre::CompositorManager::getSingleton().create(COMPUTE_COMPOSITOR_NAME, RESOURCE_GROUP_NAME);
Ogre::CompositionTechnique* technique = compositor->createTechnique();
technique->getOutputTargetPass();
Ogre::CompositionTargetPass* compositionTargetPass = technique->getOutputTargetPass();
compositionTargetPass->setInputMode(Ogre::CompositionTargetPass::InputMode::IM_NONE);

// Creating the compute pass
m_computeCompositionPass = compositionTargetPass->createPass(Ogre::CompositionPass::PT_COMPUTE);
m_computeCompositionPass->setMaterialName(COMPUTE_MATERIAL_NAME);
m_computeCompositionPass->setThreadGroups(Ogre::Vector3i(2, 0, 0));

// Rendering the contents of the scene after compute the pass
compositionTargetPass->createPass(Ogre::CompositionPass::PT_RENDERSCENE);

// Activating the compositor
Ogre::CompositorManager::getSingleton().addCompositor(m_viewport, COMPUTE_COMPOSITOR_NAME);
Ogre::CompositorManager::getSingleton().setCompositorEnabled(m_viewport, COMPUTE_COMPOSITOR_NAME, true);

Here is how I try to update the named constant for my compute material every frame. The uniform value does not change each frame like it's supposed to.

// udt is supposed to be the time since the last frame but putting in a frame dependent value instead for debugging. Nsight shows that this value does not change between frames.
m_computeCompositionPass->getMaterial()->getTechnique(0)->getPass(0)->getGpuProgramParameters(Ogre::GPT_COMPUTE_PROGRAM)->setNamedConstant("udt", callCount * .001f);
callCount++;