HP Thin Client reports "unknown" serial number in HPDM, can't be imaged

Ever since deploying HP Agent 4.7 to some of my thin clients, about 10% of them after the update are reporting the following into HPDM.Key points:

1. Device Serial Number reads 000000000
2. BIOS Version: Unknown
3. Asset Tag: No Asset Tag

And then, when I try to send an .ibr image out to them via non-PXE deployments, I get the following error message:

2017-05-08 12:55:15	Map repository to: Master Repository
2017-05-08 12:55:15	Successfully sent task to the Device Management Gateway
2017-05-08 12:55:18	Task has been retrieved by the Agent.
2017-05-08 12:55:56	[Error code: 1074176] [Module: Agent] [Category: Unsupported task]
2017-05-08 12:55:56	[Error Details]: Deploy image using repository Master Repository.
Failed to download t5740_2017-5_ff52.ibr from /Repository/Images/t5740_2017-5-ff52.
Failed to execute DeployImage task.
ErrorCode: 1074176, Error Info:  ..\..\Task\wins\ImageTask_XPE.cpp@253:	Wireless network does not support non-cached imaging.
2017-05-08 12:55:56	Failed to execute common task.
2017-05-08 12:55:56	ErrorCode: 1074176

The key thing seems to be

Wireless network does not support non-cached imaging.

However these clients don't have wireless cards in them at all. I am 100% sure I am not sending the task to the client with the "cache" option selected; these machines have very small SSDs in them so I know cache doesn't work. Yet the clients, or the HPDM, thinks that they're sending to a wireless network.

How can I fix this?