Hi, I don't know if this is still a thing but... I switched (forced to) from my trusty desktop version to the online version of Quickbooks. I have to enter over a hundred transactions per month on to Quickbooks and it was so slow.

I tried everything that I could find (and I do have a super fast internet connection and a fast computer) as a last ditch effort, I downloaded and installed the Opera GX browser, boom.. everything was super quick, in fact no matter how fast I type and change windows etc. there is no lag.

Usually I do everything in Mozilla Firefox and it's great, but for Quickbooks online, Opera GX is the way to go.

Give it a try.