diff --git a/src/web/server.py b/src/web/server.py
index da77ccb..e618514 100644
--- a/src/web/server.py
+++ b/src/web/server.py
@@ -818,7 +818,7 @@ class WebServer:
         # ── Block toggle (UI: PATCH /api/blocks {id, enabled}) ──
         @app.patch("/api/blocks")
         async def toggle_block(data: dict, channel: str = "guitar"):
-            """Enable/disable a block by its fx_type id."""
+            """Enable/disable a block by its fx_type id — sets both enabled and bypass."""
             from ..presets.types import Channel
             pm, pl, nam, ir = self._channel_deps(channel)
             if not pm:
@@ -834,11 +834,12 @@ class WebServer:
                 for b in preset.chain:
                     if b.fx_type.value == block_id:
                         b.enabled = bool(enabled)
+                        b.bypass = not bool(enabled)  # <-- added: sync bypass with enabled
                         pm.save(preset, channel=Channel(channel))
                         # Reload pipeline if needed
                         if pl:
                             pl.load_preset(preset)
-                        return {"ok": True, "id": block_id, "enabled": b.enabled}
+                        return {"ok": True, "id": block_id, "enabled": b.enabled, "bypass": b.bypass}
                 raise HTTPException(status_code=404, detail=f"Block '{block_id}' not found")
             except Exception as e:
                 raise HTTPException(status_code=500, detail=str(e))