Pulling sensation on achilles near insertion

J77

For the last 6+ months I've been dealing with a mean case of Insertional AT. I've combed through these threads but can't really find the answer I'm looking for. I've been going to Physio for almost 3 months now and while the stiffness is almost gone (finally) I've noticed a new twinge in that area. Lately, I've noticed when I stretch my tendon I have this tugging/pulling sensation. The best way to describe it is this way:

Each time I stretch my achilles I feel like the tendon is stretching over a "balloon". It feels like it's going to pop at any second if I continue stretching. It doesn't hurt but it doesn't feel right either. I don't push through it for fear of a setback.

I don't know if this is a normal feeling for AT once the stiffness goes away. I'm  curious what some of you may have experienced in your recovery.