Hi @Anonymous ,
Could you tell me:
Whether you want to show the ID in label when you selected a record?
If so, I did a test but unfortunately I did not meet the same situation as yours.
It works in my side.
Here is the steps of my test:
1.Set the text property of label as below:

2.Publish this custom form.
3.Selected one record and click Edit.
4.I choose the ID “4”, and in the label, it show “4” dynamically.

5.When I add a record and it will show the ID which I selected just now:

6.When I selected ID”10 record” which I created just now, it will show the “10” in the label:

If I have any misunderstanding, please correct me.
Thanks,
Arrow