Contact phone numbers stored with (0)
I have many domestic Australian numbers store as international numbers as I (used to travel a lot) - e.g +61 (0) 8 9555 1234. Recently I found that when I call these numbers from within Australia i get a recorded message from my telco saying "The number you have called is not available from this service". I found that I could manually call these numbers by manually dialling (e.g.) +61 8 9555 1234. However, if i included the leading 0 for the area code, which appears on my dial pad as +61 (0) 8 9555 1234, I also got the recorded message about the number being unavailable from this service.
I suggest that one of the more recent IOS updates may have introduced a bug in the dialling protocol (e.g. maybe it tries to send the brackets as well as the numbers, or maybe it no longer likes the unnecessary "0" in the area code) or introduced a bug. This is a very recent issue so maybe IOS 15.2?
I have worked around my problem by taking out the unnecessary 0 in the area code, but I've had these numbers stored this way for many years and the problem has only recently started.
iPhone 13