Since about a month ago, my Vodafone signal gets lost as soon as I get into Supa Centa in Northwood, Christchurch. Turning the phone off and back on usually gets the signal back, for a minute or so before it is lost again. Going flight mode, waiting for 20-30 seconds then turning the mode off, has the same effect.

At first I thought the issue was with my phone, until I found other Vodafone users using different types of phones have the same issues, which non-Vodafone users do not experience. This is the only area I do not get signal where I used to get, regardless of indoor or outside. Is there such a thing as signal dead spot? Any solutions?

EDIT: The signal metre would still show some good signal strength, but with an exclamation mark. Sometimes there is no exclamation mark, just like if everything was good, but no data can be consumed. Sometimes only data is affected, other times voice and texts are affected too.