Razer Nari Ultimate is just turning on while charging HELP

I bought my razer nari 2 months ago and today I realised that after charging last night when I unplug it it doesn't turn on. I think the battery is good so I don't know what happened. Right now I can just use it while is charging in the Razer Synapse when I unplug it it still says that is charging whith full battery.
I'm going to leave here my pc specs I don't know if it may help:

• Intel i7
  
• GTX 1050ti
  
• 16gb ram
  
• 1tb HDD and 252ssd
  
• I don't know the motherboard
  

Please help me this is a real expensive headset so I can't just buy other