Puppy will not stop pooping inside at work

TLDR; potty trained puppy will not stop pooping on the carpet at work

I have a 6 month old mixed breed pup who has been coming to work with me 3 days a week since August. My girl is completely potty trained at home with the occasional accident when we are taking too long to let her out, but otherwise she has been perfect and can understand that the backyard is where she goes to the bathroom. For context, home and work are not the only indoor places my puppy has been- she has been to indoor daycare multiple times without an accident, visited my boyfriend's mom's house, and been inside a family friend's house with no accidents each time. I know that these instances with no accidents could be due to her feeling nervous- my girl is scared of all new environments right now and will usually hold her bladder when she is uncomfortable. However, she is very comfortable at work and knows her way around the place as she has been coming here with me for so long. My issue is that for the last 3 weeks or so, she has been sneaking away from me while I'm working and taking poops at the back door where i usually let her out. She usually does this without giving me any indication that she needs to go, and often it will be RIGHT after she has already been outside. I am at a loss as to why this is happening, but my top ideas are that she has either not transferred the concept of potty training to this new place, or she is testing boundaries as she has officially entered her teenager stage. There is another dog here so it is possible she is marking as well, but I feel like that isn't likely since we live with another dog at home and she never does this with him. I apologize for the long post, but if anyone has any insight I would love to hear it 🙂