Hello

I tried to solve this issue but no chance!!! 

I have a Deco S3 and it connects to Huawei modem 

My contract speed is 40 fibre optic and the speed test give me 38~42 so it's great 

Now the problem is not stable! It's taken to long to open a YouTube or any website or games 

I asked the ISP and they told me to change the MTU to 1400 but it's not possible to find it? 

Any idea of how to make it possible? 

Thanks a lot