I've seen that the azureml-defaults package has been updated to version 1.41.0 updated in the past 2 days. https://pypi.org/project/azureml-defaults/
Since that update, I've been unable to update my web service as when the pip was installing the requirements for this dependency - it was left at the below stage in the screenshot.
It tries to run for 90 mins then times out. Was working perfectly before this update. Have tried decreasing the version as well and doesn't seem to work.