Thanks for highlighting this. I can reproduce what you’re seeing in the PAC. I created the following 2025.06-ext4 models based on the Basic Workspace.
PeronWithCompany_CDM.json (2.1 KB)
PersonWithCompany_CFM.json (23.8 KB)
PersonWithCompany_COM.json (1.9 KB)
PersonWithCompanyAndPeople_CDM.json (4.9 KB)
PersonWithCompanyAndPeople_CFM.json (24.4 KB)
PersonWithCompanyAndPeople_COM.json (1.9 KB)
There are a few things that you should note:
- Your use-case, “show the total number of Wohnraumschutznummern that are linked to that PersonObjekt” is actually a Query → this should be handled differently
- Your CDM based solution leads to very large amounts of data being loaded when the Form is opened. You could be loading up to 102 linked documents in your case which could lead to performance problems (see 1.)
- Modeling this large CDM will cause performance issues in both the Form and Overview. See Query model to select datasets, CDM to select fields for the overview - #2 by mcaemmerer for reducing the amount of data loaded in the Overview.
- You should, model a simplified CDM and Query as mentioned.
That being said, there are still some options open to you.
Use two CDMs
You can use two separate CDMs and reference one in the Overview and the other one in the Form.
This allows you to:
- Reduce the amount of data loaded by the Overview
- Display the to-1 Linked Field Values as required (here Company Name)
- (Keep your CDM-based Computation - not recommended but possible)
This is why I have added two CDMs to the post as I have done exactly this. Against my own advice 
I’ve kept the CDM based computation and only used the simplified CDM for the Overview.
Alternatively, you could reduce the CDM as I did in Query model to select datasets, CDM to select fields for the overview - #2 by mcaemmerer for the Overview and use your simplified CDM with a custom Query for an efficient solution.
If you need support on the implementation of the Query, please reply as a linked topic.