I have OnePlus 5T phone with unlimited US and Canada minutes, unlimited texts, 5G data with voicemail, call display and a number that has been ported over. When I receive a phone call from Amec FW / Wood PLC in Vancouver, it will ring once or twice and then hang up or I will answer it and nobody is there. When I call the number back, everything works fine. The individuals that are calling me say that it rings and rings with voice never picking up and some times the call is dropped... I think it drops when I pick up. I'm pretty sure my voice mail will pick up after 6 rings for anybody else. Anybody know why this is happening?