Slight Post Break-Up Anxiety

About four months ago I got into a relationship with someone who meant a lot to me. I didnt know I was a rebound, or at least avoided the existing fact because of how smitten I was by her. In late-August she randomly broke it off with me after telling me I wasnt making her happy, my personality was wrong, and etc. without warning. I thought we were good. Yea it hurt, but after that night I took it upon myself to heal and move on.

Its been a whole month and Im doing well. However, I discovered she never broke it off with me to heal from her previous break up as she claimed, but in fact she got back together with her ex that told her to kill herself and shamed her body when they were together before I stepped into the picture. Again, that pained me slightly because of the truth being out, but recently Ill see her viewing my IG stories lately within the past couple weeks.

Does anyone know why she takes upon herself to do this when she chose to drop me? Do I ignore it? I dont check on her, never made contact, and whenever I see her viewing my activity it sort of triggers my anxiety post-break up. Im still going to the healing mode and doing well, but its sort of a bother