The Duke/Margrave of our capital was also Sponsor of the army. The army's home region was the capital. The Duke paused and the army then had no Sponsor. A new Duke/Margrave was appointed to the capital and he did not become the Sponsor and had no Command options to do so. The old Sponsor unpaused but he's not the Sponsor anymore either. No one's the Sponsor and no one has any way to do anything about it.
There is a bug somewhere in there, right?