Please take a random process from ecoinvent 3.9.1 (a process which is original from ecoinvent without any user modifications) and perform a "direct calculation" and create a product system with "only link default providers". You will get the same results for direct calculation, for product system calculations and I guess for SimaPro (I assume they implemented IPCC 2021 similar or equal to the ecoinvent 3.9.1 IPCC 2021 implementation). Together with your own foreground processes, of course, there are possibilities that your providers might be different in direct calculation, product system calculation and SimaPro, since it depends on your own provider settings inside the processes and your providers from auto-linking or from manual linking in the model graph.
I can see from your picture, that Transporto and Materiali (the last two processes) are equal in the direct calculation and in the product system calculation. So you have to check in your other processes, if you have set exactly the same providers in your own foreground processes and in the same way in the model graph of your created product system. The "direct calculation" takes always the default providers (one fixed "hardwired" provider per exchange). The product system creates a new linking, depending on the user setting (ignore default providers, prefer default providers, only link default providers). You can also try to check your calculations with "only link default providers".
