Good Afternoon, @accounting440.
It's great to see you back in the Community. I hope you're having a great day so far.
I see that you created another thread within the Community about the same problem. My colleague already provided some helpful information about getting the Canada sales tax rate back in your QuickBooks Online (QBO) account. Here's the link to the thread.
In the meantime, you can check out these articles to help your business in the future:
If you run into any problems with the sales tax rates again, just let me know. I want to ensure that you're able to get back to running your business. Have a great rest of your day!