When you create a new link, the cooldown timer is activated. If you then send/receive as indicated, the result does in fact take place. It confused the heck out of me when it first started, but with some testing I found:
Links from before reset do not always activate the effect, you must sometimes create a new link after the 9:00 am and 9:00 pm resets.
The cooldown timer is triggered when the relevant link is created, I'm assuming based on the "use trade ability" tag.
The cooldown timer does NOT indicate the ability is not available. It is still available once, as indicated by the description.
When in doubt, bounce the marks a second time with fresh links on each end.
I was able to confirm this does work, in spite of the timers incorrectly leading one to believe the ability is on cooldown.
I hope that helps.