As this issue more focus on Office activation, I would remove the tag of “windows-remote-desktop-services”.
The Office KMS Host requires a minimum of 5 client computers to activate them, if the count is less then 5, you would get this error.
I find an article "0xC004F038: The computer could not be activated" error in KMS activation", please pull down to the bottom of article, there is a script which could be used to rearm Office and generate new, unique Office IDs.
In this script, replace XX with the appropriate value, based on your Office version:
XX = 16 for Office 2019
I suggest you try it to check whether it could help increase the number of client computers in the Office KMS pool, then you may activate clients manually via Ospp.vbs options below.
cscript ospp.vbs /sethst:xxxxxx
cscript ospp.vbs /act
More information, please refer to: Scenarios that use ospp.vbs
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