Has anyone managed to fix QBO and keep it working as it should?

I have followed all the guides and tried all the suggestions and it maybe works a little while or then just goes back to being slow!

When populating invoices some of the boxes hang for 20-30 seconds! - my browser will pop up saying the site has crashed due to waiting!

I had a little luck installing QBO as an app in Microsoft Edge but even that is rubbish now.

So far I've put a new SSD in my desktop and upgraded the RAM - didn't help.

The help I receive from the QB support is generic and unhelpful. Rather than admitting they have a server problem of whatever it is?

If it wasn't such a hassle to start again I'd use another invoicing platform but I don't want to make a whole new customer database.

Losing to will to live :(