Same thing happens to me/ After running the update, it shows up update highlighted
I think there might have been a misunderstanding in this post, the OP said the button was "highlighted", which means the light-grey background as when you hover it with the mouse, so I thought he had strange issues with mouse handling or the update was possibly stuck.
I think there's a confusion in terms because, the Update is always Active, meaning it's clickable (but not "highlighted"), and that's completely normal it would be like that.
The Update button is not an indication if a product IS updated, its Active status is controlled only by fact if the product is installed or not, it's not supposed to tell you if your products are updated because, in order to check if they are, you must...click Update!
The button should have probably be called "Check for Updates", but that didn't fit in the screen.