Causes
- Bluetooth stack bug on the stock firmware — RG556 owners report headsets stuck in a loop of losing and regaining the connection (for example QC35 headphones) and other accessories that are detected but never complete pairing. The stock Android 13 Bluetooth stack on the Unisoc T820 has connection-stability bugs that later FOTA builds improved.
- No low-latency audio codec support — The RG556 negotiates standard SBC/AAC for Bluetooth audio and lacks aptX Low Latency, so earbuds and headphones show noticeable audio delay. The lag is especially obvious in rhythm games and fast-paced shooters where audio sync matters.
- Bandwidth contention with multiple devices — The RG556's single Bluetooth radio struggles when several devices are connected at once: a second paired controller gets heavy input lag, and running audio plus a controller at the same time causes dropouts.
- Corrupted pairing cache — After firmware updates or repeated re-pairing, the stored pairing records can corrupt, producing devices that connect for a second and then drop, or that never establish a link at all.
- Wi-Fi/Bluetooth coexistence interference — Several owners report Bluetooth and Wi-Fi failing together on the RG556. The shared antenna region means a busy Wi-Fi link can stomp on Bluetooth, causing audio stutter and controller disconnects while downloads or streaming run.
How to Fix
- Unpair, reboot, and re-pair — Go to Settings → Bluetooth, tap the gear icon next to the device, and choose Forget. Reboot the RG556, put the accessory back into pairing mode, and pair it fresh. This clears most one-off connection loops.
- Clear the Bluetooth cache — Go to Settings → Apps → Show system apps → Bluetooth → Storage → Clear cache (also clear cache for "Bluetooth Media" if present), then reboot. A corrupted pairing cache is a common cause of connect-then-drop loops on this device.
- Update the firmware via the FOTA app — Open the preinstalled FOTA Update app and install any available update; Anbernic has shipped Bluetooth stability fixes for the RG556 in later builds.
- Force a media-only (A2DP) connection — If audio keeps dropping, pair the headset, open its Bluetooth device settings, and disable the "Phone calls" (HFP) profile so the RG556 only uses the media profile. A2DP-only links are far more stable on this device and fix the connect/disconnect loop in most cases.
- Use wired audio for latency-critical games — For rhythm games or fast shooters, plug into the 3.5mm headphone jack (or a USB-C audio adapter). Bluetooth audio on the RG556 has inherent delay because it lacks a low-latency codec — no settings change removes it entirely.
- Manage controllers carefully — Pair game controllers one at a time, and for two-player sessions connect the second controller with a USB-C cable instead of Bluetooth. Community testing on the RG556 shows the second wireless controller lags badly, while a cabled one works reliably.
- Reset network settings as a last resort — Go to Settings → System → Reset options → Reset Wi-Fi, mobile & Bluetooth to wipe all Bluetooth corruption, then re-pair your devices. If a specific accessory still loops after that, test with a different headset or controller before assuming the RG556 is at fault.