haglund’s and achilles

Hi,
I have haglund’s deformity and have asked questions concerning this and I have another question about something else I discovered by accident. When I push the outside of the ankle toward the back of the heel, soemthing feels like it moves into the achilles area, then I keep moving my ankle and it “pops” back into place. Is this the haglund “bump” moving or something else? And is this normal?
thankssbrewer