HDMI arc doesn't make a sound on Polk mini sound bar

So I bought the Polk mini sound bar and connected the optic cable to the cable streamer and the hdmi arc cable to the tv (so that I could hear music from cable streamer while the tv is of).
I changed the settings on my lg smart tv so that audio will come from the hdmi arc and used it for my Xbox one.
Everything worked just fine until one day the hdmi arc just stoped making sounds.
So now I can hear everything from the cable streamer that connected with the optic cable but nothing from the hdmi arc.

I've checked the tv settings and they are still on hdmi arc like before.

Any suggestions as to what will be my next step?
Thanks in advance