Where are you looking up the numbers?
What is your SAP HANA revision?
What are the exact commands you use?
Generally there is no way to change a procedure and have it use an execution plan that was compiled for a previous version. That works in no DBMS that I know of. As the procedure got changed a new compilation is required.
One major contributor to recompilation though could be the change of underlying/depending objects.
If there's a lot of changes happening there, this might explain what you're seeing.
Cheers,
Lars