I'm not sure I can say it's solved.
Our best guess so far is:
1-Footwork reduces its own cooldown to 15 seconds, which is exactly how long Footwork lasts.
2-You can use that to reactivate Footwork immediately before its Cooldown is restored to normal.
3-If the reactivation request is delayed, it might reach the server AFTER it has restored the Cooldown to normal which will cause it to see the request as spam.
I added a check to prevent Footwork from reactivating immediately and this seems to have solved the problem. But since the disconnects were random I can't be 100% sure. Also this check significantly reduces Rogue's effectiveness.
So , yeah, maybe, kinda solved.