Issue with multiple portals on one layout in a 3 table many to many database

Hello everyone,

I once again find myself asking for your help, since I am fairly new to FileMaker and don't know where to start.

As I mentioned before (for those who haven't seen my previous question), I am currently in the process of preparing a historical database of officials delegated to supervise order in private estates. The existence of both the officials and the estates needs to be confirmed by historical sources. So the 3 tables are: Sources, Jito (the officials) and Jito-shiki (the jurisdictions in estates). One source can mention multiple officials and estates; an official may appear in many sources and hold jurisdiction in numerous estates; lastly, a given estate may appear in multiple sources and may have been under the jurisdiction of numerous officials during that time period - this led me to conclude that this is a many-to-many-to-many relationship.

Each record has a form view with its own fields as well as most essential information drawn from related tables via portal. I allowed for the creation of new records, so that I only need to type in the missing details in related tables and everything worked - so far, so good. Thanks to you I managed to solve my initial issue regarding adding multiple records via portals, but ran into a new one. Right now, when I try to add multiple officials (jito) and estates (jito-shiki) they show up properly on the source layout, but after checking the individual records for the officials, they all list the same, first estate; likewise in estates, they all show the same official - the first one I typed in. Is there any way to relate those two portals so that the officials and estates in each row are tied together? The relationship graph is below.

Thank you in advance for your help.