diff --git a/android/app/src/main/kotlin/me/kavishdevar/librepods/bluetooth/aacp/AACPManager.kt b/android/app/src/main/kotlin/me/kavishdevar/librepods/bluetooth/aacp/AACPManager.kt
index 03b46cb38..5f6532818 100644
--- a/android/app/src/main/kotlin/me/kavishdevar/librepods/bluetooth/aacp/AACPManager.kt
+++ b/android/app/src/main/kotlin/me/kavishdevar/librepods/bluetooth/aacp/AACPManager.kt
@@ -1181,7 +1181,16 @@ class AACPManager(private val device: AppleDevice) {
                     val payload = data.command.payload.toByteArray()
                     val timestamp = Clock.System.now()
                     if (payload.size == 18) {
-                        val heartRate = payload[1].toInt()
+                        // unsigned: a signed read turns anything >= 128 bpm negative and drops it
+                        val heartRate = payload[1].toInt() and 0xFF
+
+                        // bit 0 of the last byte is set for the first few samples after the sensor starts (payload[2],
+                        // which looks like a confidence value, is also very low then); those readings are unreliable,
+                        // e.g. 169 bpm at rest, so skip them and stay in WAITING until the sensor settles
+                        if (payload[17].toInt() and 0x01 != 0) {
+                            Log.d(TAG, "skipping heart rate sample while the sensor is acquiring: ${payload.toHexString()}")
+                            return
+                        }
 
                         // same as healthconnect's datatype. 300 isn't possible anyway, but whatever
                         if (heartRate !in 1..300) {
@@ -1202,7 +1211,7 @@ class AACPManager(private val device: AppleDevice) {
 
                         Log.i(
                             TAG,
-                            "hr: $heartRate bpm"
+                            "hr: $heartRate bpm, payload: ${payload.toHexString()}"
                         )
 
                         val heartRateSample = HeartRateSample(
diff --git a/android/app/src/main/kotlin/me/kavishdevar/librepods/devices/AppleDevice.kt b/android/app/src/main/kotlin/me/kavishdevar/librepods/devices/AppleDevice.kt
index 595a791b9..803957cff 100644
--- a/android/app/src/main/kotlin/me/kavishdevar/librepods/devices/AppleDevice.kt
+++ b/android/app/src/main/kotlin/me/kavishdevar/librepods/devices/AppleDevice.kt
@@ -16,6 +16,7 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asSharedFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.getAndUpdate
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import me.kavishdevar.librepods.bluetooth.MacAddress
@@ -124,8 +125,13 @@ class AppleDevice(
     }
 
     override fun connect(): Boolean {
-        _connectionState.update {
-            ConnectionState.CONNECTING
+        // the service (ACL/UUID broadcasts) and the UI can both call connect(); only let one of them open a socket
+        val previousState = _connectionState.getAndUpdate {
+            if (it == ConnectionState.CONNECTING || it == ConnectionState.CONNECTED) it else ConnectionState.CONNECTING
+        }
+        if (previousState == ConnectionState.CONNECTING || previousState == ConnectionState.CONNECTED) {
+            Log.d(TAG, "connect() ignored, already $previousState")
+            return previousState == ConnectionState.CONNECTED
         }
 
         val success = aacp.connect() // && att.connect()
diff --git a/android/app/src/main/kotlin/me/kavishdevar/librepods/services/LibrePodsService.kt b/android/app/src/main/kotlin/me/kavishdevar/librepods/services/LibrePodsService.kt
index df87fe626..eb2617b0c 100644
--- a/android/app/src/main/kotlin/me/kavishdevar/librepods/services/LibrePodsService.kt
+++ b/android/app/src/main/kotlin/me/kavishdevar/librepods/services/LibrePodsService.kt
@@ -24,6 +24,7 @@ import android.os.BatteryManager
 import android.os.Binder
 import android.os.Build
 import android.os.IBinder
+import android.os.Looper
 import android.os.ParcelUuid
 import android.os.ext.SdkExtensions
 import android.provider.Settings
@@ -308,6 +309,8 @@ class LibrePodsService: Service() {
                     }
                 }
 
+                // createDevice() already registered observers for this device; cancel them so each state change is handled once
+                deviceJobs[MacAddress(bluetoothDevice.address)]?.forEach { it.cancel() }
                 deviceJobs[MacAddress(bluetoothDevice.address)] = mutableListOf()
 
                 deviceJobs[MacAddress(bluetoothDevice.address)]?.add(observeAppleState(device))
@@ -676,7 +679,9 @@ class LibrePodsService: Service() {
 
                     Log.d(TAG, "updating island window")
                     if (islandWindow?.isVisible == true) {
-                        islandWindow?.updateBattery(state.battery)
+                        CoroutineScope(Dispatchers.Main).launch {
+                            islandWindow?.updateBattery(state.battery)
+                        }
                     }
 
                     Log.d(TAG, "updating notification")
@@ -919,6 +924,14 @@ class LibrePodsService: Service() {
         reversed: Boolean = false,
         otherDeviceName: String? = null
     ) {
+        // the island is a window, so it has to be added from the main thread (state observers run on IO)
+        if (Looper.myLooper() != Looper.getMainLooper()) {
+            CoroutineScope(Dispatchers.Main).launch {
+                showIsland(device, type, reversed, otherDeviceName)
+            }
+            return
+        }
+
         Log.d(TAG, "Showing island window")
 
         val state = device.state.value
@@ -1221,7 +1234,9 @@ class LibrePodsService: Service() {
         }
 
         if (new == EarPresence.NONE && islandWindow?.isVisible == true) {
-            islandWindow?.close()
+            CoroutineScope(Dispatchers.Main).launch {
+                islandWindow?.close()
+            }
         }
 
         var justEnabledA2dp = false