Noise on GPIOs when combining Mesh and UART

We have an application based on

..\ble-mesh-nrf52\nrf5_SDK_for_Mesh_v2.1.1_src\examples\light_switch\proxy_server\light_switch_proxy_server_nrf52832_xxAA_s132_6_0_0.emProject

We have added UART on the pins below:

#define RX_PIN_NUMBER 17
#define TX_PIN_NUMBER 16

We run it on PCA10040

Using an oscilloscope, we observe noise in the following GPIOs:

P0.22

P0.28

P0.18

Is there any way to stop this noise?