The reason for this would probably be revealed in your code, which is apparently a state secret, and it is likely that the HC-05 is entirely innocent. You also need to be a lot more clear about what this project really is. Are you using one HC-05 or two?
Use two hc05s. I want to make a wireless Bluetooth robot hand that mimics movement.
I will transfer the flex sensor value to another hc05 and operate the motor using that value. The code is simple. the flex sensor is read using analogue read, transmitted using BT write, and received data using BT read.
The serial monitor on the computer that sends this data shows the value of the flex sensor quickly and accurately. However, the serial monitor of the computer that receives the data shows irregular and inaccurate data.