I am having this exact issue. I also have a 2019 Roku Express. The other channels are working (if slower than i like to load) but not netflix.
Thanks for the the post.
Can you please explain the issue that you are experiencing?
Have you tried removing the channel from the Roku home screen by navigating to the channel tile, pressing the * key on your remote and choosing 'Remove channel'. Then restart your device from Settings>System>System restart. Once your player starts up again, add the channel back once more.
Does this clear up the issue you are seeing?
Thanks,
Danny