German release dates get constantly declined

For years, I've been adding German release dates without any problems. In the last months, however, submissions get constantly declined because the IMDb editors are "unable to verify" (my source is allscreens.de, the German association of motion picture distributors). The thing is that this behaviour only applies to release dates, other data (like distributors, certifications, cast members) gets accepted without issues. Can you explain why IMDb editors are so restrictive regarding release dates? I mean, this one of the most basic information that is missing (with IMDb sometimes the only movie site where this information is not included, e.g. "The End of Oak Street" which opens next month) where submissions can be easily verified with a Google search or by visiting allscreens.de.