I had just ended a phone call when I had to make another. I could not, I tried several numbers and they all ended right away! This was all within a minute or so. Eventually I could make a call. The only thing I could think of was that it was using Edge to check my mail. But without a warning or anything I really have no clue. Just "call ended" , thats all. Oh, and if it was rhe mail, ir may have been waiting for the prior call to end. That is the "check mail" was pur in a cue. If so, how frustrating to end one call bur not be able to make another promptly.