i want to use notifier to report bluetooth disconnection and also hide some item, inside clock event
There might be something useful in the search for 'bluetooth' in this community. You can find stuff like this by using the magnifying glass at the right page top.
Currently, BT does not give a reliable indication that the connection is lost.
You will have to use your own code to decide if the connection can be deemed lost.
We can't see from your Block whether you are sending or receiving.
I send a text to BT every 20 or so seconds to test if it is still connected.
If not, a screen error will be flagged and I use that to propt the error to the user.
The call notifier block has no function here other than keeping my phone awake.