I have lots of missing transaction, I am not sure why this happened, but now I am not sure if the calculations being done on the platform is accurate or not.

Thanks for posting in the Community, @mayiptyltd .

I'm here to help with sorting your missing transactions and getting a fixed to your calculations in QuickBooks.

If you could provide more details on what are the transactions that were missing and what calculations do you mean in QuickBooks. I'd be glad to assist you further and give an accurate response to your concern.

As a way around, let's perform some browser troubleshooting steps to get rid of the unexpected behavior.

To start, let's log in and access your account in a new incognito or private browser. This way, you'll know if it's your browser causing the error. Below are the keyboard shortcuts for your reference:

• Google Chrome: press Ctrl + Shift + N.
• Mozilla Firefox: press Ctrl + Shift + P.
• Internet Explorer: press Ctrl + Shift + P. 
• Safari: press Command + Shift + N.

Then, you may clear the cache in the one that you're currently using if it works. The steps are provided in this article: How do I clear my browser cache and temporary Internet files? 

But if you still have the same error, switch to a different browser application then login and access your account from there.

Please feel free to let me know what you meant. I'll do whatever it takes to ensure your concerns are addressed. Have a good one!