I have had this occur on different Channels like the Roku Media Player where I accidently hit "don't ask me again".
Sometimes I have had to Remove the Channel, Restart the Roku device, and add the Channel back. I did notice that I also had to toggle the bandwidth saver from on to off and then vice-versa. The message did not immediately reappear but did come back and after an extended time of viewing (probably past the 4hr limit of the bandwidth saver).
There is no way to immediately trigger that "don't ask me again" with just a menu press (as far as I know). It will appear again when it runs up against the Roku bandwidth saver setting though. This little info box only popped up on certain channels/apps and I actually assumed it was just a leftover bug from the 9.2 OS of Roku that introduced the bandsaver saver option. There used to be a "hidden way" to enable and disable, but this has been removed.
The only way to get it to appear immediately would be to perform a Factory Reset of the device. This will return the device to original settings. However, you will need to perform the initial setup and login to all your subscriptions again.
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
Insignia RokuTV, Ultra 4660x, Premiere+ 3921, Express 4k+ 3941