you could add a loader to the page to distract the user

most web apps do this - even simple apps like gmail

just create a float that covers the whole page with a loader gif on it and use “when page is loaded” to hide it

if you’re referencing data in a repeating group then you could also use “when repeating group loading is no” to hide it

possibly the data you’re trying to access in the dropdown is quite heavy which is why it takes seconds to load it