@KrunalDoshi is right, you may need to delete your current Report Designer application from your computer, and install the new version. Please see the back and forth responses on this post, but I think the new version of Report Designer was required somewhere around 24R1 if I remember correctly.
2025R1 upgrade, now I can't log into Report Designer | Community
Here are the Builds where you can go into the Version > Build > Acumatica Tools
builds.acumatica.com - /builds/
As mentioned, you won’t need to do this each time you upgrade, but starting in like 2024R1, there was a new Version of Report Designer that you will need to open reports.