XPS 15 - Windows 10 Pro - Why am I all of a sudden getting Widows Activation errors

You may want to post a screenshot.

Make sure it is legit.

This means your organization -- wherever you obtained the Windows license - has a key management server for which the license is about to expire.  Contact your IT department (it sounds like WIndows was obtained from a corporate or educational organization).

One additional thought here: If you're using KMS licensing because you have a personal PC that was imaged with an organizational image and you no longer work with that organization, then technically your PC isn't licensed to keep running that Windows installation, so this is working as designed.  But if your personal PC has it own Windows 10 license, you should be able to remove the KMS client key and reactivate using your digital entitlement that would have been obtained during the Windows 10 upgrade, assuming you actually ran the upgrade while it was set up as a personal system.  If you never ran a formal upgrade and instead just laid down a Windows 10 image, it's possible that your system never claimed its own actual upgrade.

But if you're confident your PC does have a proper digital entitlement, you can remove the KMS client key by opening an elevated Command Prompt and entering "slmgr.vbs /upk", which uninstalls any active product key and will definitely cause Windows to fall out of activation.  At that point, you can then have it reattempt activation by running "slmgr.vbs /ato", and if you don't have a key entered, it will attempt to activate with a digital entitlement.

^ Either that, or you haven't had a network connection to your organization's key management server in a while.  I think Windows expects to check in with the KMS server at least every 90 days or so.  Basically, with a KMS server, client computers get short-term leases to run Windows, which need to be renewed periodically.  That's how Microsoft eliminated direct key management requirements for clients without allowing PCs licensed via KMS to simply remain licensed forever.  Newer versions of Office work the same way.

But whether you haven't checked in with the KMS server in a while or they need to update their KMS server, you should contact your organization's IT department about this message to find out what you or they need to do.  If you need to do something, it will probably just involve VPNing to your organization to get a network connection to the KMS server, and then they'll probably give you a command to force a communication attempt rather than waiting around, and at that point you'll be good.