The prices on Raison are showing the initial or follow-on placement purchase price. In simple words - this is the price which was actual when the last issuer distribution was processed.

Orderbook.io is the secondary market where the price is dictated by users demand. It can vary depending on the last executed orders. You could wait and see if some users will close the dip. Then you will be able to sell higher or buy lower.

Also due to the low liquidity on secondary with Ordrebook.io you might get better results by doing small trades every other day, so that the price could be moved back by other users if there is demand or offer.

If the asset is already public but still traded on Orderbook.io - this asset is yet a tokenised asset, which is backed by the publicly traded security. There also might be a price difference which generally should be equalised by the arbitragers.