我认为这是 Sequential Executor 所期望的.Sequential Executor 一次只运行一件事，所以它不能同时运行心跳和任务.

I think it is expected for Sequential Executor. Sequential Executor runs one thing at a time so it cannot run heartbeat and task at the same time.

为什么需要使用 Sequential Executor/Sqlite?切换到其他 DB/Executor 的建议非常有意义.

Why do you need to use Sequential Executor / Sqlite? The advice to switch to other DB/Executor make perfect sense.