I can report I’m experiencing the same problem:
WP 4.3.1, Events Maker 1.6.6, Polylang 1.7.9
Pll URL settings: language is set from content.
WP permalinks settings: /postname
Category archive pages URL is [domain]/category/[category slug], for all languages (no language slug in the URL with my settings).
When using the Pll language switch menu from a category page, the href is [domain]/[language slug]/[category slug], which will go to the front page (default 404 behavior with Pll, I believe), instead of the category page of the translation (the url shoud be [domain]/category/[category slug in the chosen language] with my settings).
I have also verified that the problem only happens with Events Maker active; with EM deactivated archive pages work as expected.
Thanks.