UI5 app performance Vs SAP GUI

hello

we are seeing big differences in performance between our UI5 app for order entry, versus performance in SAP GUI

SAP is much much quicker for us, then UI

everything from opening the homepage, entering lines, product pricing etc

we do have latency between the server and end user of 200ms, but 20 to 30 second load times is way over the top just for the home page to load.

we also see 5 second save times for our orders.

anything you can suggest for us to look at