Why am I missing one record from the output of a Dynamic Shapefile Writer?

I have the need to utilise a dynamic writer for coordinate conversion of a user uploaded file.

The schema will be unknown therefore the need to be dynamic.

I am using FME (20201027 - Build 20787)

I have used a writer transformer and have set the schema to Dynamic and the schema is set as "Schema From Schema Feature".

I am wondering if this has an impact on the first feature being used to dimension the dataset and is not written to the table. However this would be unusual because I have used these writer transformers before with more success.

The noted difference I can surmise would be that the schema and features have been split up after the reader and I have used the schema to determine the coordinate system of the incoming dataset features to check that it conforms to the eventual conversion, then the features and schema are brought back together using a Joiner transformer.

This works for other formats (CSV and TAB) with which I have used the same logical design.

The cached records seem to read as fine all the way to the writer.

What I have found is that if I add a connector into the writer (from the same output of the previous transformer which the dynamic schema also uses, and accept the defaults (output filename etc) the extra record appears in the non-dynamic output.

So I have a feeling it has something to do with the dynamic nature of the writer, and some setting that I am missing?

Kind Regards,

Cameron