BMW e60 4x4 Issue

[Zitsw]

Hello everyone,
After a long trip after i stopped i heard a weird sound under the car and got a few messages on my dashboard 4x4, abs, dtc, brake. After that I didn't drive that car on a long distances, most of the time it was parked near to my house. I read a lot of forums where everyone saying that you need to replace actuator motor which i ordered and was ready to replace, but when i took my car on another small trip i heard a sound which coming from under the car and if the first sound was only when i started car or turn it off, this sound coming even if i'm rolling or accelerating. Now i changed my actuator motor and did a calibration for the TC, 4x4 error didn't pop up a mile of drive and i still heard a clicking sound under the car while rolling, after a mile i still recieved a 4x4 issue.
What can cuse that sound and why changing my actuator motor didn't help to solve the 4x4 issue, i'm thinking that noise under the car can cause the driveshaft but can it cause 4x4 error or the sound is not connected to 4x4 issue.