Flying High Boxes have disappeared from inventory since maintenance

[rustic hinge]

Summary:
I was keeping some Flying Skill Training Support Boxes, Flying Level Growth Support Boxes and one Flying Mastery Support Box to use after the event "Flying High" ends. All of those boxes were set to expire in 20-something days. When I logged in today, I realized that those three types of boxes have disappeared from my inventory.

Difficulty:
Advanced 🙁

Occurrence:
Always/new occurrence.

Details:
I had also bought a couple Mysterious Spirit Stones (300%), Alban Knights Special Divine Fruits and Rebirth Potions from the Flying High Event Shop, and those didn't disappear. I unfortunately have no screenshot of the boxes in my inventory. I read the description of the items and the event page, and there was no mention that the Flying High Boxes would disappear when the event ends, making the expiration date very misleading.

[crimson basin]

As per the text on the items themselves:

Flying Level Growth Support Box:

A box that grants a variety of potent boosts to both EXP gain and AP acquisition. When used, you will receive the combined effects of a Royal Combat EXP Potion, Yellow Prism, Orange Prism, and Elixir of Happiness for 1 hour, as well as a Rebirth Potion (Event).

Only usable by those chosen as Main Characters for the Flying High event, and cannot be used while you have any effect active that would not stack with the effects this box provides.
(This item will be removed once the event ends.)

Flying Skill Training Support Box

A box that contains the knowledge and expertise to train a skill to its maximum rank. When used, you will be prompted to choose a skill from among those you have already learned but have yet to reach their highest rank.

Only usable by those chosen as Main Characters for the Flying High event.
(This item will be removed once the event ends.)

[rustic hinge]

Oh shoot 🙁 I was reading the description from the event page, since I had not access to the item description anymore. I'll be starting the grieving process then...
"Expires in 30 days.
Not Tradeable.

When used, you’ll train all skills of your talent of choice to their maximum rank. Does not train Dan Ranks."

[crimson basin]

You are right that this information appears to be missing from the event post itself. I'll forward that to the relevant peeps.

Thanks for the report. RIP to your boxes though. 🫡

[rustic hinge]

Thanks for the help