For an ePO managed environment, when the deployment task runs it executes the detection script of the products that have been configured to be installed.
The symptom you describe, of the installation being launched each time the task kicks off, suggests the detection script is _not_ finding some key data points that would tell it VSE is already installed. Consequently, it will result in the download of the installation binaries from the repository and launching the installer.
The installer at that point may find the product is already installed, and do nothing. Next time the deployment task runs, the same process repeats.
So, you may want to engage our Support team to investigate the health of the system - and verify that the necessary data points exist on the node to allow the detection script to successfully determine the product is already installed, and correct affected systems as needed.
The investigation may require capturing data (with Process Monitor) when the deployment task runs so we can see where the detection script is looking, but more importantly I think, what is happening when it's trying to query those data points.
I'll suggest to navigate to VSE installation client task and uncheck the option "Run at every policy enforcement (Windows only)"