Bug introduced with phone numbers in international dialing format
As part of a recent update phone number links from the user profile pages that are in international dialing format are now broken.
A phone number might display as +1 234 567 8901 when you select it the phone attempts to dial 2B12345678901 which obviously does not work.
2B is of course the hex value of the ASCII character '+' so it seems there is a fairly simple bug in how the information is being passed between OWA and the phone application.
Presumably an openURL call is being made with a URL that should look like "tel:+12345678901", but there is a bug in there somewhere.
Previously this worked OK, but was broken some time in the last few months.
I am seeing the same issue. International format numbers, even US numbers dialed from within the US, do not work. Very limited usefulness.