Reproduce:

1. Create a fresh Fabric profile with Fabric API and Language Reload
2. Run the profile and select any language
3. Create a world with cheats enabled, use /gamemode creative
4. Try the search on creative menu

Expected:
The search to find items by the selected language

Actual:
The search works in English, even though the item names are translated

Edit: this commit of a similar mod might help: ChachyDev/lazy-language-loader@029aafb

Fixed in Language Reload 1.2. Curseforge version is currently under review.