SAP Business One 10 DI API compatibility

Hi,
we have developed an extension that is working fine with B1 9.2 and 9.3.

We are testing it on B1 10, and it's not working.
I would try to understand the compatibility, do I need to reference DI v.10 and recompile ?
Once done, will it work backward on B1 9.x ?

Any help reference about it ?

From SDK Help Center:
An application initially developed with SDK release X will also run with the interfaces and components of SDK release X+1 without any changes.

Thank you
Paolo