Thanks for posting here in the Community.
Did you restart your Roku Soundbar before re-installing the Hulu channel? That step is crucial when performing the troubleshooting. If you haven't tried the suggested order (remove > restart > re-install), we suggest giving it a shot once again.
We also recommend restarting the soundbar from the Settings menu by navigating to Settings > System > System restart > Restart.
Let us know how it goes!
All the best,
Roku Forum Moderator