Can't put a watermark

I have been trying to add a watermark in my videos so viewers can subscribe more easily but after following all the steps mine doesn't appear... I have made sure that the background of the watermark is transparent and that I am logged in when updating the watermark. I have also tried to see one of my videos using another account but it still doesn't appear. Any idea why this is happening?
Maybe you need to try re sizing it? I don’t know mine use to show up and for some reason tonight’s it’s not showing up in the bottom right hand corner.
I think it takes a while if you're adding a watermark for the first time. Mine took a few days before it started appearing on videos but once it was on, I could change it instantly.