Calls dropping when merging
I have an iPhone 8 plus on Verizon. Phone calls are fine. I can put a call on hold, switch back and forth with no problem. As soon as I try to merge calls for a conference, it drops both calls. I’ve done every reset, pulled the sim card, Verizon has reset my phone from their end. After all that it may make one successful conference call, then back to dropping. Is anyone else experiencing this ? Thanks
iPhone 8 Plus, iOS 11.2.5