>Please raise Lithuania's rank up to a Kingdom, I don't understand why it's not considered at such when the Grand Principality of Vladimir is and beside that, Gediminas was a King, Lithuania has various principalities(duchies) as vassals, it's quite large by 1337, it just fits for them to be considered as such
No, it is WAD. I personally did the research about it, on academic articles. The obvious problem is that the rulers of Lithuania were adopting the Russian-style title of 'Grand Prince', which was not so easy to translate. However, it arises from the recorded documentation that in the negotiations between Gediminas and the Pope about his potential conversion to Catholicism, that he asked the Pope to be recognized and crowned as King; and after the conversion of the Grand Duke Jogaila (better known as Władysław II Jagiełło), that the country adopted the title of 'Grand Duchy of Lithuania', which it kept, instead of becoming the 'Kingdom of Lithuania'.

BTW, side comment: we obviously have an event chain about the Lithuanian conversion, with 3 paths - converting to Catholicism, converting to Orthodoxy, or stating as Romuva: