You can't clear the cache on Roku devices because they don't have one, but restarting your streaming stick, box or TV can address buffering issues.
Depending on how badly your Roku is behaving, you can either perform a restart from the Settings menu or do a factory reset.
Hit Home three times, Up twice, Right, Left, Right, Left, Right. Once done, the Developer Settings are activated, exposing advanced diagnostics and system logs, while the regular menus are hidden.
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