When Hiya Spam Blocker is set as your default phone app, Android routes call audio using the same Bluetooth priority it applies to any default phone dialer. If a Bluetooth headset or car stereo is paired and connected, calls may automatically connect through that device.
If you use a Bluetooth headset or car stereo
This is expected behavior — Hiya Spam Blocker inherits Android's standard Bluetooth routing for the default phone dialer. When a Bluetooth audio device is connected, Android routes calls through it automatically.
To route a specific call to your earpiece or speaker instead: Use the audio routing button on your in-call screen to switch to earpiece or speaker during the call.
If calls are routing through Bluetooth unexpectedly
If you're not intending to use a Bluetooth device but calls are routing there anyway:
Go to Settings → Bluetooth and disconnect any paired devices you don't want to use for calls
Force-close Hiya Spam Blocker (swipe it away in the app switcher) and reopen it before placing a call
Test whether the routing issue persists
Still having problems?
Contact support from Settings → Help and Support in the app. Include your device model, Android version, and the type of Bluetooth device involved (headset, car stereo, speaker, etc.) so the engineering team can investigate.