Colossal Surge bug?

Upgraded Colossus Engine gem to level 3 via Colossal Surge Event, then upgraded normally and the option was still upgrade to level 3; after upgrade gem was still level 3, should it not now be level 4? /scratch head

Device Type: PC
Device Model:
Device Operating System: Win 10
Diablo Immortal App Version:

With the items collected via the Event, you can upgrade the gem’s QUALITY (from 2/5 to 3/5 and so on), “normally” you upgrade the gem’s RANK (from 1 to 10).

EDIT: You can also upgrade the gem’s quality when upgrading “normally”, if you use a higher quality gem as “fuel” for the upgrade. If you have a 5/2 rank 3 and use a 3/5 and enough gem power to upgrade it to rank 4, the result will be a rank 4 quality 3 gem.