Welcome aboard to the Community. I can share some information about how you can improve the overall performance of your QuickBooks.
QuickBooks Online is a web-based accounting service. It relies on your computer or device’s processing power, the available memory (RAM), and your Internet connection speed.
Also, you can run a Google Speed Test to confirm your bandwidth/the speed of your connection. This way, we'll be able to ensure the issue isn't related to your internet.
For more information, as well as some tips if you want faster access to QuickBooks Online, I recommend the following article: Why is my QuickBooks Online slow?.
Please know that I'm just a post away if you have any other questions about using QuickBooks. Take care.