Hi Alexander,
I moved to new version 26.5 and here my results:
Please see:
Comparison(left-Csv, right-Shapefile)
image.png (179.0 KB)
Test data(input/output/QGIS)
5324-Csv-Shapefile.zip (47.0 KB)
Thanks,...CSV‑to‑Shapefile conversion reports success, but the resulting...conversion You can inspect the generated Shapefile programmatically...