This thread is resolved. Here is a description of the problem and solution.
How to translate Yoast breadcrumb - Yoast page for Content Type for "Projects"
Since this is in fact admin string (the one you set in Yoast administration panel), I registered this string to be translatable through XML, and is now available within string translation:
<wpml-config> <admin-texts> <key name="wpseo_titles"> <key name="bctitle-ptarchive-project"/></key> </admin-texts> </wpml-config>
I have put this into WPML -> settings -> custom XML configuration
I think that this will clear up on what was behind this:
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