По такой же проблеме Майкрософт нам написал следующее:
"As an initial finding, this may be caused because the send timeout was configured as 10 minutes for Soap requests. More information about different WCF binding timeout can be found in our official documentation for
Configuring Timeout Values on a Binding.
As a result of the above findings, I have just raised an internal ticket with the Engineering team in order to see whether we can increase this timeout or what is their input on the best course of action in our current scenario. I will surely keep you updated!"