cat problem.

so recently me an my bf moved into our new apartment together. we brought our two cats once we got settled. before we lived in the desert they got to go outside whenever an come in at night. I don't know if this has anything to do with it but one of my cats keeps peeing on the carpet well twice she's actually peed. and right now me an my boyfriend are eating an see her sniffing around an she sits to try an pee we catch her both times. she has a little box an I always clean it she knows how to use it very well I just don't know why she's trying to pee. it's becoming very frustrating. I've heard cats don't like Citrus if any of you have any idea what I should do to get her to stop. she very healthy and nothing is wrong with her. I NEED HELP! Thank you in advance😁