SharePoint Person Field not showing values after deployment with solution

[Anja1]

After deploying the app via a solution, the people fields no longer work in the forms. In the person fields the selection values remain empty, and the dropdown does not open.

Does anyone have the same problem?

Is there a better way than deleting the fields and adding them again?

Unfortunately we have made some adjustments to the field, so it would be a bigger hassle to adjust everything manually.

I first thought it had something to do with environment variables, but in my current solution no environment variables are used.
For environment variables I have already found a post: https://powerusers.microsoft.com/t5/Microsoft-Dataverse/Data-Source-Environment-Variables-not-workin...