When finished offline install tasks, you should click the "Offline Post-install: Refresh Keys & Update" button to ensure your system is up to date and has the latest keys. After that, here are some tips and links to help you get started with CatOS.
Change common user directories to English
Run the following command in an English locale to force user directories to English:
env LANG=en_US.UTF8 xdg-user-dirs-update --force
Input method troubleshooting
https://github.com/SHORiN-KiWATA/Shorin-ArchLinux-Guide/wiki/中文输入法
fcitx official Wayland documentation
https://fcitx-im.org/wiki/Special:MyLanguage/Using_Fcitx_5_on_Wayland
Community guide
https://github.com/SHORiN-KiWATA/Shorin-ArchLinux-Guide/wiki
Recommended reading
My advice
Every Arch Linux user should take responsibility for the stability of their rolling-release system.
Complaining about breakage is unproductive; upstream changes are not the responsibility of Arch developers.