Cant Overwrite Runes on Corrupted items

I have a corrupted pair of gloves that hit a second socket, I wanted to replace the runes that I had added previously but was only able to overwrite the first socket, when trying this on the second socket it pops up with the confirmation selection but even when confirming the change it does not swap it. Any workaround for this or is this intended?

It was the cast speed one, which is indeed limited to 1 now :( Thnx for the info.