STZHD 1361 is actually showing SHOHD 1340 content

Is anyone else experiencing this issue? When I select channel 1361, which the guide lists as Starz, I get the same content that is currently being shown on channel 1340, which is Showtime. For instance, I tried to watch Black Sails (a Starz original series) on STZHD (1361), but what I saw was Shameless (a Showtime original series). Shameless was also being shown on SHOHD (1340), as it should be. Basically, I don't have Starz anymore, even though it's listed and I pay for that channel. What I get instead is two identical Showtime channels.