Insight (Mastery) + Ionian Boots summoner spell cooldown bug

If you have the Insight Mastery, and you purchase Ionian Boots, the cooldown drops from 255 seconds to 225 for a bit, and then reverts back to 255 seconds.

What's even worse, if you then sell the boots, the cooldown goes up to 285 seconds (?!?!?!). After testing, distortion works fine, the cooldown reduction is applied as intended.

If you buy the boots with the distortion buff on them all together, you will see the cooldown dropping to 191 seconds, and then it gets reverted to 225 seconds.

Please fix this as it's quite annoying. Thanks