I cite from https://orgmode.org/manual/Quoting-HTML-tags.html:
The HTML export back-end transforms < and > to < and >. To include raw HTML code in the Org file so the HTML export back-end can insert that HTML code in the output, use this inline syntax: @@html:...@@. For example:
You are hit by the new tramp-archive.el package, which regards *.odt files as an archive (like *.tar files). In order to disable this, you might add the following to your ~/.emacs:
(setq tramp-archive-enabled nil))
However, there might be an error in the org exporter, because tramp-archive is activated only for a file ...