Troubleshooting Trace Migration Between Phoenix Projects

Hi, I tried to copy all traces from a source project to a destination project in the same phoenix instance (I use the self hosted docker container). After running following code, I can see that the destination project is created but there is no traces loaded into it. df does contain data during debug. Does anyone know what could be the reason?

client = px.Client()
df = client.get_spans_dataframe(project_name=source_project_name)
print(df.head())
client.log_traces(trace_dataset=px.TraceDataset(df), project_name=dest_project_name)