After rescanning for channels, and clicking on the ‘Add to Guide’ button, the guide data takes a while, actually, sometimes a long time depending on how many channels you selected.
During this guide data download time is when your Tablo won’t work properly.
You might just need to wait.
Don’t trust the Guide Status info listed between ‘Edit Channel Lineup’ and ‘Update Now’.
If you’re using a web browser to perform the channel rescan, and add to guide parts, then you can check the actual progress of the guide data download by clicking on the hamburger icon (3 horizontal lines) in the upper lefthand corner, which expands the catagories list, and displays the actual guide download progress.
It may go thru this download process twice in a row, by the way:
