Hi @Linda,
Thank you for your reaching out and welcome to Microsoft Q&A!
Do you mean the Design view is blank, but you can see the table borders? You could try to update your VS and the Reporting Services extension to the latest versions.
Or do you mean parameters hold a blank space in the deployed RDL? Please refer to the known issue.
If you have any more issues or need further assistance, feel free to share with us!
Best regards,
Lucy Chen
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