By idle I assume you mean while the phone is suspended? It works fine for me (verizon US, phosh) though there’s an extremely rare bug where the phone will fail to resume from suspend and needs to be rebooted. Also I find I need to restart modemmanager after I boot or the modem doesn’t come online, though that may just be a problem specific to me since I think I installed the open source firmware for the pinephone modem incorrectly since there’s a bunch of other stuff that doesn’t work properly (hangs on a lot of AT commands).