Did you already claim the 8k deduction for 2023 on your 2023 return? Did you contribute to your FHSAs by transferring amounts from your RRSPs?

i did not claim anything in 2023 for FHSA and none of the FHSA amounts come from RRSPs. I tried to claim the full 16k in 2024.

Did you put your 2023 T4FHSA on your 2023 and then carry forward the deduction?