Hi @suguru26,
Greetings from the Roku Community!
We're glad to assist you with your problem with your Roku mobile app. Can you please try to restart your Roku device by unplugging it from the wall outlet for a minute and plugging it back in right after? After doing so, please restart your mobile phone too. This helps clear any temporary glitches or software issues causing your phone and Roku device to slow down or behave erratically.
Let us know how it goes, and we'll be happy to further assist you.
Kind regards,
Eunice
Eunice L.
Roku Community Moderator