I asked this elsewhere but figured someone here might have an idea...

I was looking up a rail fares for a trip I was thinking of taking and the Roomette and Bedroom prices changed when I changed the number of people travelling.

I checked:
1 traveler in 1 room
Rail Fare: $137
Roomette Add: $288
Bedroom Add: $614

2 travelers sharing 1 room
Rail Fare: $274
Roomette Add: $519
Bedroom Add: $955

I understand that the Rail fare should go up for the second traveler but in the past the accommodation (room) charge did not. The check-out page specified 1 (or 2 adults) and 1 room. Is there a reason the Roomette and Bedroom prices would go up for adding a traveler or was I missing something before? I used the same train, time, and dates when I looked up both and I went back to check again later to be sure I didn't happen to check when prices changed. I received the same result.

In this scenario could 1 traveler be booked and another added as an open sleeper so they would just pay the rail fare? I'm used to the accommodation charge staying the same so I was wondering if anyone else noticed this? It turns out I'm going to be travelling on a different day now, however I was wondering if this is just a fluke, uncommon circumstance, or the new norm?