I had a similar issue where a scheduled update went at the wrong time recently. I have a ticket open to hopefully dive into that.

This is a known bug that can happen if you're trying to use DDM Software Update workflows with devices that have earlier installed OS versions. What version of macOS was the device on where you experienced this issue? You might have to clear the DDM SU plan and issue a new one to get it to work for the device. But there are other ways a user can defer a forced DDM SU workflow. Have a look at this document and pay particular attention to the power requirements. If they are below the battery charge threshold the update won't install automatically.

It's on 15.1.1. 

Yep, This happened to us when pushing out the security update (15.1.1) from the Zero Day for MacOS 15.1.0.

@stevefitz that is not good. I had read elsewhere that this particular issue was supposed to be resolved and not occur to devices that are on macOS 15.1 or later. I would encourage you to generate a sysdiagnose file from the affected computer and submit a Feedback case with Apple. If you're part of the MacAdmins Slack instance you should visit the #appleseed channel and do the necessary work pinned to the channel to join the private channel and then you can post a message with your feedback number and experience and you're likely to get some further assistance. Feel free to look me up on Slack and I can give you some more details.

Appears to have been a power issue. My test laptop was pretty low. I let it charge for a while and the update kicked off at 30%. I hadn't checked the batter level before someone mentioned it. It makes sense though. It would be nice of Managed update message said that the update would install once the battery was charged to a certain level. 

I had also read 30% elsewhere but an Apple posted document states 50% to "install automatic software updates" so I am not sure what the real battery percentage needs to be. 

So your issue ended up being it just wasn't at a high enough power level right? 

I spoke with someone from Apple about this document and he agreed there are some errors in the document. The battery percentage thresholds for at least Macs is wrong and the download and prepare on power is also not accurate. He’s going to try and get the document corrected to reflect the actual conditions.