1) Dolby Atmos > 40Mbps to be stable and not lagging;
2) Try to play local video to confirm whether it will be intermittent back;
3) Confirm the connection method is which, the recommended connection method is HDMI ARC>Optical>Bluetooth>AUX
It may also be an interface problem, replace the other connection to see if it is still intermittent.
(4) Maybe the a problem with the cable, it is recommended to replace the HDMI2.0 standard cable above
(5) Maybe other BT or 2.4GHz devices caused by interference (recommended that the connection distance in a room and no barrier wall)
(6) Do not place it near the router.
If there is still a problem, please re-plug the subwoofer power cord and repair it.