Similarly I cannot use single-character shortcuts for such actions when FX window is open. For example, if I have the key "E" assigned to "Show/hide envelope for last touched FX parameter", it doesn't work with FX chain window open (or if the FX window is floating). Likewise for all other FX related show/hide commands (MIDI learn, parameter modulation, track control)...
I have to click on the arrange to bring focus to it in order to run those actions ("Send all keyboard shortcuts to plugin" is disabled, BTW).
This is not nice
Can this be remedied, as well?