When you say higher can you give examples? is it x100 higher? It is likely they are showing the price in GBX (pence), rather than GBP (pounds), which is what freetrade uses. So for example £MAB is currently 307 GBX (307 pence) on Google, and £3.08 GBP in freetrade
But they are all obviously the same value when it comes to it.