when the config cleanUrls is set to true (by default)
and the requested URL is a file name with an extension
and has some parameter in it ex:

/index_2.html?foo&bar=1

the server rewrite the url to

/index_2

and remove the extension AND the url parameters

those URL on the other hand works as intended :

/index_2?foo&bar=1
/?foo&bar=1

/folderName?foo&bar=1

/folderName/?foo&bar=1

question :
is it as intended ?

If the response is "yes, you should set cleanUrls to false" then the README should be mentioning those cases

but I think the cleanUrls setting should set urls like :

/index.html?foo&bar=1 
to
/?foo&bar=1 

it would be more useful