Recent biopsy says ive lost IDH-MUTANT

Hi All 12 months in from diagnosis astrocytoma glioma grade 2 IDH-MUTANT. On my 2nd craniotomy after new tumour was found (im sparing some of the details) . Oncologist gave me the jeebies saying all positive markers had gone but has just confirmed that only the IDH mutant has gone. I couldn't really understand what the implications are, as Google doctor, who must be ignored, says pretty bad things about loosing IDH mutant but the Oncologist seemed to imply this was ok news...im guessing maybe he thought the news was better than he predicted. Im confused....anyone had this scenario!