PokerTracker

I have just started using PT3 (V3.13.5 beta) for Zoom PLO. In the Summary tab, 2,363 hands of £0.10, it indicates $208.18 rake, or about 88bb/100 hands.

Can't be right, obviously. Am I misinterpreting this, or do I have some other problem?

The summary tab indicates total rake taken out of pots - even ones you were not involved in at all. That value seems a little high but honestly not all that much. Rake is pretty brutal at the lowest stakes.