The 'Visual Studio Test' task has an option named 'Upload test attachments', regardless of if this option is on or off for a release it is always uploading test attachments.
This is now occurring on two specific build agents in my agent pool and it is a change of behavior from around the end of last week.
There is no known change in release definition.
I have tried creating a new release definition and new and old release definitions exhibit this behavior.
In the past the only way we have stopped this undesired behavior is to recreate the build agents.