Quick answer: Unreal Enhanced Input chord action consuming modifier key, blocking other actions from receiving it? Set Should Suppress = false on the chord trigger.
Ctrl+Shift+S chord works. Plain Ctrl+S no longer works because Ctrl is consumed by the chord trigger.
Don't suppress modifiers
Chord trigger inspector > Should Suppress Modifier Key Events = false. Modifier passes through to other actions.
Or use mutual exclusion
Define chord actions as 'super-actions' that take priority. Other actions check the chord state.
Audit chord usage
For each chord, list which simpler actions share the modifier. Conflicts surface before users find them.
“Input chords consume keys by default. The consumption is opt-out.”
If you have chord-heavy input, build a per-modifier audit. The conflict matrix is small; ship it as documentation.