I think the problem is the calculation from the Seed Phrase to the Master Root Key, as described here:
Swapping from ledger to Trezor - #8 by skyrmion
Unfortunately I do not find the original post by @SebastienGllmt anymore.
It could be, that the CIP3/Icarus way is better than BIP39 (more iterations of the PBKDF2 function), but it is non-standard and causes a lot of incompatibility issues.