When complex address lines are searched using Nominatim geocoding API there is often no results returned. For example, if I search г. Тверь, Петербургское шоссе, д. 93, корп. 1, оф. 519 there is no result. But the search is shorten to Тверь, Петербургское шоссе, 93 к1 (no office number, just numbers for the building identification) the address is found correctly. This is certainly the problem with Nominatim itsel, but maybe there is away to affect the results returned by some request settings.