Meaning ,
when The details of the transaction are displayed on your Ledger device's screen, while I connected physically the ledger by USB I close wifi and then can verify the details and approve the transaction on the device itself and then open wifi to broadcasts it to Bitcoin network , is this true?
Ledger X is WiFi independent device, thus in the course of transaction approval it doesn't mater whether WiFi is on or off, the only matter for this is the presence of its parring with relevant software program (wallet) which is able to broadcast the signed transaction.
UPD, o_e_l_e_o is right on cue, as always. How does he manage to be here and there?