Spoils of War timer disappeared

I had upgraded my Relic Shield to Targon's Brace but I reverted it and opted for a Sightstone instead. On my way to lane I noticed that I didn't have a timer counting up the charges for the Relic Shield's Spoils of War, as seen in the screenshot provided.

I tried last-hitting a minion to see if the timer would pop up or perhaps proc the ability but it didn't work, though it did return eventually after a while. I haven't been able to recreate it since and I sent in a ticket and they recommended I post it here as well. Thanks.