Hi @Mongoose ,
Since we can't reproduce your situation, we need to narrow down the problem and try some things.
- You could try to clear browser cache then restart it.
- Try to use a different browser or your browser's InPrivate mode to see if the same error occurs.
- Change to another network environment. If you’re currently using a company network, check if the issue persists in a home network.
- Check if the same issue occurs with other SharePoint site collections.
Here is my test result, when I search the folder everything works fine.
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