Confirmed, and the cause was worse than it looked. Our portal builder was snapping EVERY portal's Y down to the nearest platform within 60px of its X. That is a relocation, not a rounding fix: HHG1's `in00` (the door to Hunting Ground II) sits at (958,-851), deliberately halfway UP the rope, and the snap dragged it 219px down onto the platform at the rope's FOOT. It is a touch-type portal, so once it was down there it fired the instant anyone stood near the rope. Only the two invented map-edge portals get snapped now; real portals keep their v83 coordinates.

(On the dev branch - it will be in the next published build, not v32.)