Here are the patch notes for version 1.5.4 for the 2025-05-21 maintenance:

Bug Fixes
-Fixed an issue where the upgrades were incorrect when exchanging 2 FWC Golden armor parts at once.
-Fixed an issue where the number of jewel slots was incorrect when exchanging a [Ultimate] K Fang +8/9/10 for a 2026 FWC Golden Curtana Ultimate.
-Fixed an issue where sorting by player name and sorting by shop name were inverted in the Shop Search.
-Fixed an issue where the 4th Anniversary letter exchange was not available on mobile devices.

General Changes
-Shops can now be sorted by channel in the Shop Search.
-Added settings to filter whisper messages, allowing players to choose between Everyone/Friends/No One.
-Unread private messages appearing in the System window are now truncated when the player's level is below 80.
-Added a warning notice regarding phishing attempts when receiving a message from an unknown player.
-Added visual effects to Party Toy Force Gem and Party Toy Book.
-Added descriptions to Ankou weapons and armor parts.

Special Thanks
Special thanks to our translation contributors for this maintenance:
-Chinese (traditional): rion-tw
-French: ocruts
As a token of our appreciation, some contributors may receive a small reward. Further details will be shared once confirmed.

Thank you.