If the contents of tab-separator element is in e.g. Ukrainian, and no ID is set manually for that tab-separator element, then anchor/href IDs are *not* automatically generated from the tab-separator element contents (that is, link ends with a sharp sign # leading nowhere).

Sample:

<h1>Вступ</h1>
Then some text follows.

Two solutions possible: either attempt the transliteration of text (approach similar to - but presumably much simpler then - the i18n-ascii.txt of pathauto), *or* generate random anchor IDs.