MASN

My best guess is, somebody - maybe Comcast, maybe Major League Baseball - thinks you live outside of the Nationals/Orioles "zone." Then again, for all I know, you may live halfway between DC and Baltimore.

I am in South Central Pa and have 2 MASN channels that has the Baltimore and DC sports.

I think it might depend on whether the local market carries it or not.

Now 15 years ago, when I used to work for DirecTV, a piece of info that I learned is that for cable systems, RSN territories were roughly determined by geographic areas like counties where Satellite was more targeted by Zip Code.  This being because the old cable boxes didn't have any way of reporting where they are sitting and they were generally assigned to a specific head end in a county or region.   Where as, for satellite, the smart card that went into your Satellite decoder was programmed with your Zip Code.  So if you moved and set up your box in a new area, you couldn't watch any sports programming until the smart card in your box was updated with the new zip code.  You don't know how many times I had to answer the age old question, "Why can't I watch (Insert Team Here) anymore, I only moved (X) miles away.  If the Zip Code you are in is outside of the market area for a team/RSN, then you won't get their games.

The General rule of thumb was that a pro sports team's general market area is about about 50-75 miles from their home stadium, unsure if that is the rule of thumb now.  So you could technically be geographically close, but it's possible that your Zip Code is just outside the market area that MASN serves.  Considering that most cable systems these days are moving to a IP based system where your programming is delivered over the internet and not directly via Coax, the whole RSN by county/cable system process may be starting to align more into what DBS did and may target by Zip Code.

Now, if you want hear something weird that kinda throws what I just said out the window.  My Stepmother lives in Hanover PA -- She gets MASN, NBCS Philly, AND AT&T Sportsnet Pittsburgh on her Comcast system and she can watch all the teams from all three RSNs.  If I go to the tool on MLB and NHL's streaming platforms, her zip code lists specifically that the Pens, Pirates, Caps, Nats, O's, Flyers, and Phillies are all blacked out on streaming because her Zip Code in Hanover considers all those teams to be "In-Market" for her to watch on her TV.  Go Figure!