AITAH for telling my GM that an agent is breaking rule on tv and as a result i now take the remote or lock it away

This happened a few days ago II work in a hotel and for this week at least I am doing the overnight shift so 11pm-7 am. My hotel is pretty relaxed for this shift there's no one really coming down, the doors are locked so I am protected, If I want to play games on my phone I can. Etc. There is a tv about 75 feet from the front desk next to the fireplace to my left. We are allowed to watch tv during this shift as well with some exceptions. No crime and No gore and obviously no nudity or corn.... In the off chance someone comes down to the lobby or something. That night, I was working with someone, and I asked if they wanted to take control of the Tv. They said yes and immediately changed it to a true crime show. I being a supervisor told them, Hey I like crime shows too but we can't watch this in the lobby. They handed me the remote and I changed it to a food network show. Because there are two of us I went to my lunch break when I got back 30 min later, I saw that she had switched it back to a true crime show. I asked for the remote and told her AGAIN we aren't allowed to watch these shows at the front desk. She tried to argue with me that no one is going to be coming down anyways. Its super late No one would know. I let her know again I would know, I don't want HER to do something to have the owners take that privilege away, I wasn't going to let her mess up the few perks we do have for working this late. I switched the tv completely off at this point and put the remote in my drawer and locked it. AITH?

Update- I did a surprise visit yesterday and saw her again watching a crime show. I sent her home and talked to the Gm this morning. Let him know what happened we have now decided when she is working night audit and I am pm I take the remote and lock it in the Gm's office so she can't watch tv at all