Daisy! (Ivern's ult) attacking inhib [GAMEPLAY]

I cannot push R to redirect/retarget Daisy! on enemy inhib. She just stands there and walks around it. I was clearly pressing R and clicking on the inhib several times and she did nothing until I retargeted, using R, to a minion.

I would post a screenshot but its just Daisy standing next to enemy inhib doing nothing so it doesnt show much. Anyone else have this problem?