It seems that since yesterday, (QBO) on my laptop hasn't been loading properly. There's been a significant delay, and it's resulting in a prolonged period of white screen

Welcome to the QuickBooks Community, accountant-quick. I've got steps to ensure you have the best QuickBooks experience by properly loading it during use.

Once you are experiencing pages that haven't been loading properly in QuickBooks, below are three possible scenarios that may be causing the problem.

• Your company name has special characters that are not allowed.
• There are two or more adjacent dollar signs ($$, $$$, etc.) in any list or transaction data that would appear on the page that's not fully loading.
• You are trying to access QuickBooks Online with more than one browser tab simultaneously. 

To fix this, let's perform some troubleshooting procedures to fix them. Before doing so, I recommend making sure that you clear your browser's cache and internet temporary files first. 

Once done, you can read this article on how to fix the loading problem in QBO based on the scenario mentioned above: QuickBooks Online doesn't load correctly or has blank pages.

If the issue persists, I recommend contacting our QuickBooks Online Support Team. They have the tools to pull up your account in a secure environment and be able to investigate the cause of why the program has been not loading properly and why it keeps happening.

Here's how:

1. Select the Help (?) icon in your QuickBooks Online company.
2. Enter the topic you need help with in QB Assistant. 
3. Choose Contact Us to connect with a live support agent and select a way to connect with us.

In case you need to see the performance overview for QuickBooks Online and how it improves it, you may refer to this article: Why is my QuickBooks Online slow?.

Let me know if you have any other concerns or questions about the managing QuickBooks product, accountant-quick. I'm always ready to lend a helping hand. Take care!