AD5933 and RENESAS microcontroller are connected by I2C communication. Both SDA and SCL are connected with 10KΩ pull-up resistors, and bypass capacitors are not attached. During the evaluation test, when I briefly shorted both ends of the pull-up resistor

AD5933 and RENESAS microcontroller are connected by I2C communication.
Both SDA and SCL are connected with 10KΩ pull-up resistors, and bypass capacitors are not attached.

During the evaluation test, when I briefly shorted both ends of the pull-up resistor connected to SDA with tweezers to make the communication data abnormal, communication with the AD5933 became impossible even after the tweezers were released. rice field.
Even if the initial command is sent from the RENESAS microcomputer, communication does not recover.

Communication returns to normal when the AD5933 power is turned off and then turned on while the RENESAS microcomputer remains on.

I would like to know what could be the cause.
thank you.