Welcome to the Community!
Sorry to hear you're having trouble with your TiVo®.
It's OK to reboot the box, you won't lose any of the recordings or data you have.
Just switch the box off at the mains, leave it off for a minute, then switch it back on. Once it's booted back up you can check the guide to see if the data has loaded properly.
Let me know how it goes and give me a shout if you need anything else.
All the best
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