Guild Wars 2

I lost a +5 agony infusion last night because I tried to put a versatile infusion into the second slot in the ring (defensive slot). I was going to try again tonight but when I went to add it, I got a message saying that would destroy the +5 agony infusion already in the agony infusion slot.

What should I do? Is there special order to add infusions to rings/back pieces that isn’t written anywhere that I could find?

The second slot is only for +x Agony Infusions that were release with Fractured. All other infusions are for offensive/defensive/utility slots. The offensive/defensive/utility slots won’t take the +x Agony Infusions either.