GrandStream 100 offhook sound after hangup

Hello, I have a granstream 100 and a gxp-2000.

If i call eachother, and hangup on the 100, the gxp-2000 will hangup also.

If i call eachother, and hangup on the gxp-2000, the 100 will start beeping and i have to manually hang it up.
It does that after some macros i got also…im sure it has to be a gs100 setting anyone know which one i should change?

thanks