Power BI Error: the underlying connection was closed an unexpeted error occured on a send power bi

[MAXIM_UVAROV]

Hello!

I have m-script which retrieves data from one custom web api. 

This script works perfectly in power query under excel, but when I try to run it under the latest Power BI from time to time it gives me an error:

But sometimes works well and it retrieves data. I can't figure when it gives an error. 

I've send a frown. 

How can I repair it?