Triss was forced to hide from Geralt many things for other members of the Lodge. This, as per their order, or if you like, guidance. They all knew and feared Geralt, especially so now he has amnesia. They knew perfectly well what this morally decent, helping fellow can achieve if he targets or pursues anything.
They had a secret organization, knowing many things, actively mixing in politics, scheming and even conspiring against a certain king and his life, even planning to steal part of his lands for the Lodge's interests. Their pitiful excuse was their desire for a stable and more powerful north, and place in court for those damned sorceresses. Plus they knew both about salamandra and the neighboring realms and rulers' ambitions/movements against temeria, or if you prefer, against temeria's best interests for itself.
As Triss reveals when you go to save her in second game, the other women stopped trusting and calling her in talks. Not only they directly used and discarded her, but they also manipulated partly Geralt and his memories, either through her, or themselves (like Sile in 2).
That was awesome. In the first game, you get such a nice play to captivate your interest, and your curiosity and need to learn about it and explain it fully, cannot be sated but only at the end of the second game. Very clever that one. Great tricks CDPR can pull. Nice going.