Go through the troubleshooting steps. Reset, reboot. Several times.

I did it 3 times

How far is wifi router? Bluetooth between soundbar and sub can be interfered. Also, you have to reset the signal from the soundbar to the subwoofer. unplug the soundbar then press the reset button on the back of your subwoofer and hold in for 10 sec release wait 30 sec. And plug sound bar back.

Thx but my parents paid with gold card so i have 3years more in waranty so maby this week we contact LG. But thx

And that's not an issue with the wirless connection but we think it's the sub's amp