Export Generates SDR File instead of 32 Bit HDR File

Issue: When you choose to export 32 bit HDR files, the generated file does not always contain HDR information.

Lightroom Classic Version Number: 13.4
OS Version Number: Windows 10

Steps to reproduce:
1. Merge several exposures to one HDR .dng file in Lightroom Classic
2. Do not develop the HDR file. In particular, do not activate the HDR option in development mode.
3. Export the HDR file as 32 bit HDR TIFF file (other file types not tested, but probably same result) - see screenshot

Expected result: The generated file contains the HDR information as in the original .dng file, as chosen in the export dialog.
Actual result: The generated file just contains SDR information - to prove this, re-import it to Lightroom Classic, then check it visually, and with the histogram in HDR mode.

I use HDR TIFF files for stitching of HDR panoramics in an external tool. Then I do the tone mapping and development to create the final SDR image.