Indeed, Russia's case in this conflict would be more sympathetic and justifiable than IRL if Russia's intention was merely to solve it according to the national self-determination standard.
Unfortunately, Russia is far more interested in solving it according to the spheres of influence standard, which it was pretty close to succeeding at through hybrid means (highly integrated combination of low intensity warfare, diplomacy, and intelligence operations).
-Ukrainians starts thinking too much about being buddy buddy with EU (whether its sympathy to the west, salivating at EU generosity to poor countries or both, doesn't matter) and overthrow Russia friendly establishment which got asked by Kremlin to block that, and did it like good ol' Kremlin boys they are.
-KGB nobility says this cannot stand and there have to be consequences. A pretty clever plan is devised. They will set up an insurgency in the most pro-Russia part of Ukraine to make a bit of a mess, everyone knows EU and western media are super sensitive to this kind of a mess, no EU for ya hahaha. There is a bit of fighting, Ukrainian army, which is kinda useless according to intel reports flails around uselessly. Eventually Russia moves in as big damn peacekeepers, ends the war, and dictates the peace plan - which will be that the most pro-Russian regions will receive autonomy within Ukraine, and that autonomy will come with preferably legal, or at minimum de facto veto powers over Ukraine's foreign policy and related decisions. Of course that will be meant to be used first and foremost to prevent Ukraine from closing too much to the west.
Also swipe Crimea in the chaos, because fuck paying Ukraine for renting the military bases forever. Russia is not America, it's not made of money, sheesh.
-Things go according to the plan. At least at first. Crimea swipe is a great success, Ukrainian army is about as surprised and useless as predicted. Unfortunately that doesn't last, they start getting their shit in order after some time and pressing on the insurgency hard. Russia needs to become more aggressive with support to ensure they don't get crushed, which is supposed to be secret but shit happens, which in turn has all sorts of political consequences in Russia, Ukraine and the western countries.
-Ukrainian military advance is slowed down enough for international diplomacy to work and the plan seems salvaged, the name of the game is Minsk Agreement which has the necessary elements at least in general wording.
-However, the little cracks in the plan seem to be widening and ruining it. The fighting was a bit too long and too intense, in that too much grievance between the sides was created to get them to kiss and be friends again, and enough infrastructure damage was done for the area to become a bit of a hot potato rather than valuable real estate, while westerners may be seeing too much through the plan and supporting Ukraine more than they are supposed to, especially after not falling for the "no Russian forces" cover, which in turn makes it harder to make Ukraine just bow to pressure and go along.
-Things get mired in status quo, Russia's hope is that the next president is their guy, or at least manipulable and can be persuaded to get the plan back on track. The discussions over diplomatic solutions get dragged out in excessive lawyering and shouting as Ukrainians seem to know what's the plan with autonomy and try to lawyer the wording in a way that doesn't serve the plan, which in turn cannot be accepted, more lawyering and shouting ensues.
-Elections in Ukraine happen, and the next president also turns out to be a disappointment for Russia. More bickering and lawyering. Separatists are getting harder to control, do unsightly stuff, life.
-Putin starts to think that the plan is stuck, needs some adjustment or a good hard push.
And its a good time to do this, because the current team in Washington looks less threatening than anything before it, especially after Afghanistan bungle, and is pretty distracted with economy and corona stuff to boot.
-We are here. The format of negotiations is changed to negotiations at gunpoint, including plans to pull the trigger if the right set of conditions arises.