XSLT-formatted property values are not updating through the OFSC Plugin API

Summary:

We are experiencing a production issue with a custom hosted OFSC plugin, reproduced in TEST. The underlying values of XSLT-formatted properties are not updating through the plugin, although REST PATCH updates them successfully.

We use three activity string properties, represented here by aliases:

• X: Stores raw XML without XSLT formatting.
• Y and Z: Store the same XML with XSLT formatting configured for display.

All three properties are configured for the plugin. Before submitting a Plugin API close message, the code assigns:
result.Y = result.X;
result.Z = result.X;

Our observations:

• The plugin closes normally, and X saves successfully.