From the NHC 4am Discussion:
"Helene is sending some mixed structural signals this morning. On
one side, an Air Force Reserve Hurricane Hunter aircraft reports
that the central pressure has fallen to near 966 mb, and satellite
imagery shows the eye is trying to clear out. On another side, the
aircraft reported concentric eyewalls of 16 and 32 n mi diameter,
with the maximum flight-level winds, 80 kt at 700 mb, occurring
about 50 n mi southeast of the center likely in relation to the
outer eyewall."

I don't recall any hurricanes 90mph or less with concentric eyewalls or seeming to go through an ERC. I find it quite odd and wonder if it will hinder its top end speed while it loses time going through these physical structure changes. It only is forecasted to have 10 more hours over water....