bluenrg232 lose connection

[LJ.1]

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[LJ.1]

I use bluenrg232 in my custom board. Everything seems ok except it always lose connection after a short connection (10 sec about) with my phone , then i can reconnect it .  If i put it for a long time (30 min for example), then it disappeared in phone bluetooth scan list,  only after i poweroff and reopen it , i can connect it again

. The devkit board is the same condition with the demo application