Fix multiple optional argument sorting

discord/ext/commands/core.py

@@ -577,6 +577,10 @@ class Command(_BaseCommand, Generic[CogT, P, T]):
             ctx.bot.dispatch('command_error', ctx, error)
 
     async def transform(self, ctx: Context, param: inspect.Parameter) -> Any:
+        if param in ctx._ignored_params:
+            # in a slash command, we need a way to mark a param as default so ctx._ignored_params is used
+            return param.default if param.default is not param.empty else None
+
         required = param.default is param.empty
         converter = get_converter(param)
         consume_rest_is_special = param.kind == param.KEYWORD_ONLY and not self.rest_is_raw