This problem started a couple weeks ago and is getting worse. Sticks are plugged into wall outlet. The basic problem is that I can't load anything until I unplug/replug the sticks. Here is the product info:
Model: 3810X
S/N: YH00G5533717 & YH00DP537026
Software version: 10.5.0 build 4208-50
The problem seems to be worse on the system we use the most. Lots of loading new programs, etc. It also has more buffering. Laptops connected to the same network have no problem.
See if this is the cause of your problem.
Roku operating system version 10.5 added added a new "Power" item in the "Settings > System" menu for some of the newer Roku devices. The new "Auto power savings" item there will put your Roku device into a low power standby condition after a period of inactivity, such as when your tv has been turned off for a while.
Pressing a Roku control key (like HOME) on your Roku remote (not Power, Volume, or Mute which act on the TV, not the Roku) should bring the Roku out of standby and back to full operation. Pulling the power for a few seconds to restart the Roku will restore full operation as well.
If you have a "Settings > System > Power" menu item, deactivating the power saving option you find under "Auto power savings" should prevent your Roku from going into standby in the first place.