This feature comes from Blynk 1.0. And we got no complaints about it in the last few years. So we decided to keep it. The idea is that once triggered you don’t need notifications again and again. If the sensor value comes back and after a while threshold is met again - you get a new trigger again.
Later we introduced an ignore period. And now with the ignoring period seems like this limitation is no longer needed. However, we can’t just revert it, because there are already running systems that relies on this behaviour. So we’ll see what we can do.