I shall report formally the problems mentioned in http://lists.gnu.org/archive/html/emacs-orgmode/2019-04/msg00240.html, trying to isolate them as much as possible. I'll start with the simplest (and, IMHO, the most annoying).
Whereas the HTML exporter correctly recognize a source block as such, the LaTeX/PDF exporter does not. This can be demonstrated in a (minimal) org file using *only* the built-in tools (no external packages), where a source block is labelled as such by the HTML exporter but as a figure by the LaTeX exporter.The generated LaTeX source shows a suspicious "\captionof{figure}{\label{orgf2d4160}" in the export of the source block. Further tests (not shown) show that the proble persists when org-mode is set up to use the minted package for LaTeX export of source blocks (minted is indeed used, but the block is s still mislabeled). This example also exhibits some cosmetic problems (spacing) that will be ignored for now. The org source and resulting pdf and html files are available here : https://drive.google.com/drive/folders/1bQmaefiztW9ZDRNLcjOD_WbEmTg4d8dG?usp=sharing