diff --git a/web/src/components/config-form/theme/fields/HardwarePicker.tsx b/web/src/components/config-form/theme/fields/HardwarePicker.tsx
index fb2bcb72ef..1ee1a12867 100644
--- a/web/src/components/config-form/theme/fields/HardwarePicker.tsx
+++ b/web/src/components/config-form/theme/fields/HardwarePicker.tsx
@@ -15,6 +15,7 @@ import {
   hardwareForDevices,
   MAX_DETECTORS,
   recommendedDetectorCount,
+  resolveUnitDevice,
 } from "@/utils/detectionHardware";
 
 type HardwarePickerProps = {
@@ -60,9 +61,13 @@ export function HardwarePicker({
       return [];
     }
 
+    const assigned = devices.map((device) =>
+      resolveUnitDevice(selected, device),
+    );
+
     return selected.units
       .map((unit) => unit.device)
-      .filter((device) => devices.includes(device));
+      .filter((device) => assigned.includes(device));
   }, [selected, devices]);
 
   /** Spread `count` detectors round robin over the selected units. */
@@ -200,7 +205,7 @@ export function HardwarePicker({
                 <Checkbox
                   id={`${idPrefix}-${unit.device}`}
                   className="size-5 text-white accent-white data-[state=checked]:bg-selected data-[state=checked]:text-white"
-                  checked={devices.includes(unit.device)}
+                  checked={selectedUnits.includes(unit.device)}
                   disabled={disabled || Boolean(claimedBy)}
                   onCheckedChange={(checked) =>
                     handleUnitToggle(unit.device, checked === true)
diff --git a/web/src/utils/detectionHardware.ts b/web/src/utils/detectionHardware.ts
index 622cf4f184..bf7676604f 100644
--- a/web/src/utils/detectionHardware.ts
+++ b/web/src/utils/detectionHardware.ts
@@ -21,10 +21,31 @@ export function hardwareForDevices(
     return undefined;
   }
 
-  return hardware.find((entry) => {
-    const known = new Set(entry.units.map((unit) => unit.device));
-    return devices.every((device) => known.has(device));
-  });
+  return hardware.find((entry) =>
+    devices.every((device) => resolveUnitDevice(entry, device)),
+  );
+}
+
+/**
+ * The unit device string a configured device refers to.
+ *
+ * A config may leave the index off, such as "edgetpu:usb", which the detector
+ * resolves to the first unit of that kind.
+ */
+export function resolveUnitDevice(
+  entry: DetectionHardware,
+  device: string,
+): string | undefined {
+  const unitDevices = entry.units.map((unit) => unit.device);
+
+  return (
+    unitDevices.find((candidate) => candidate === device) ??
+    unitDevices.find(
+      (candidate) =>
+        candidate.startsWith(`${device}:`) ||
+        candidate.startsWith(`${device}.`),
+    )
+  );
 }
 
 /**