Since you asked about changing channel, you must be cognizant of the signal interference caused by other radio signal emitting devices. If changing channel does not help, you may want to consider switching to 5GHz band if you are close to the AP and your devices support it.
Changing channel does not help all the time because channel usage is shared by many, and other devices in your vicinity on auto channel select may sometimes share your selected channel from time to time. it is a trial and error process. Good luck.