Hello,
This is simply how the wireless operates.
Both, access point and client interfaces use the same radio device. When RUT950 connects to the access point as a client, physical radio is restarted in order to create a new logical interface, reconfigure it and apply new settings.
The solution to avoid this would be to either use a device with two separate radios, for example, one for 2.4GHz, the other for 5GHz, or have a second device, to perform the role of an access point or a client station only.
Best regards,