Hello
I'm testing the firmware using the BLE.
When I upload, I can see that the board is working.
Also, I don't think there's a problem with running each line of debugger.
However, if connect the BLE in the nrf connect app, nothing comes out as shown in the picture below and it doesn't connect either.

There was no problem with this firmware code until the day before yesterday. Last time I tested with other cell phones, there was a problem that couldn't be connected. Maybe the connection hasn't been good since.
I've never had a problem like this before, can you tell me the cause?
Thank you.
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The connection was successful again after repeated the program build... The connection seems too unstable.