I'm new to Resolve so please answer this in small simple words!
I've created a complex effect with lots of nodes, but now overall its a bit heavy and I need to back it off by mixing the effect 80% with the original media. I understand I can do this using a Layer Mixer node, with one input connected to the previous node in the chain, and the second input connected back to the output of the first node in the chain. Then use the Post Mixing Gain slider in the Key tab of the Layer Mixer node to adjust the effect amount. Makes sense. However the effect remains at full strength regardless of where I position the slider!