That's an awkward Ukraine you've got there. For a Ukraine which is independent without having the western regions (where the Ukrainian nationalists are, a situation which has only changed to any great extent since 1991), there are a few possibilities:
- A PoD back before the Ruin (which raises questions about the Crimea and Odessa).
-Being willed into existence by some powerful sponsor, probably German (which raised the question of why it doesn't have Volhynia and even some its of Podolia).
-Overlapping with the last one, a very funny ending to the Russian Civil War. Very quick guide to the RCW in the Ukraine: it was contested by four factions in shifting alliances: Reds (wanted Ukraine united with Russia), Whites (didn't believe in Ukraine), Blacks or Makhnovites (didn't believe in much except defending themselves and their communities), and the Ukrainian directorate. The Poles and the Entente also stuck their noses in. In OTL's circumstances, nobody had much chance except the Reds. The Blacks were a small facton with a largely peasent base of support and were going to be disposed of by the winner as soon as his position was secure, as the Reds did OTL. The Whites aren't much help to us because even if they somehow took over Ukraine and nothing else (if they haven't won the RCW, which is just about plausible if you really stretch it but is going to leave Russia as a big fat mess for some time), then whoever reigns in Moscow can squahs them), it would be South Russia and ruled as such. So for an indepedent Ukraine, you really need something to go massively wrong for the Reds combined with a conerted Polish-Entente efort to prop up the Directrate (which never really excerpted any control over the Donbas and the Black Sea cities: they were in these Red support bases briefly by the grace of the Germans). It's going to have to be outright offensive war against the Bolsheviks by everyone.
-And on this general subject, what's happened to the Kuban? If the Moscow government has been soundly gang-banged, I would inagine a jumble of states in the North Caucasus, but that border looks odd.