This bug has existed since at least v10, it has been reported and ignored a number of times, and it’s very disruptive of any reasonable workflow. There must be at least some acknowledgement of it. It’s not hard to describe at all:
On certain VST3 plugins, the “value” box on the info line shows the current value of the parameter for all automation nodes.
It doesn’t show the actual value for the node: instead, it shows the current value of the parameter, and hence the same value for all nodes. Any attempt to edit this value has no effect after pressing enter. It doesn’t happen with all plugins: for example, all iZotope and Valhalla plugins are affected, but FabFilter’s are not.