Translate text stopped working

Hi! Just ignore the use of nested arrays of text. This json text used to be valid up to 1.21.4, and now (1.21.5) it still is considered valid but just prints "container.shulkerBox.itemCount" instead of correctly translating and formatting the text. I've checked the changelog but haven't found anything about it. Any help? [ [ { "translate": "container.shulkerBox.itemCount", "with": [ { "translate": "block.minecraft.red_sandstone", "fallback": "Item" }, { "text": "32" } ], "color": "#FFFFFF", "italic": false } ] ]