I’m fairly sure you are hitting CodeCov Uploads from Azure Pipelines are failing with 'Build numbers do not match' - #10 by X-Guardian (where the Azure API returns an different SHA on merge commits.
I would see if you can confirm, then watch that thread.
Not yet. We are trying to reduce the usage of all the uploaders to a single one, but it’s a slow process and we are trying to make it as least disruptive as possible.