Hi TN-3220,
According to the articles linked below, Win10 1909 Enterprise is supported until May 10, 2022. The Windows 10 Pro 1909 version went out of support on May 11, 2021.
https://learn.microsoft.com/en-us/lifecycle/announcements/windows-10-1909-enterprise-education-eos
https://learn.microsoft.com/en-us/lifecycle/announcements/windows-10-1909-end-of-servicing
According to these articles, once the editions reach the end of their support no updates will be released. Therefore, it's not possible to apply Enterprise updates to the Pro version.
You will need to update these Win10 machines to later versions.
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