Why didn’t White House lawyers manage the Ukraine conflict of interest?

From WSJ: By James Freeman , Nov. 26, 2019 5:38 pm ET

It is my understanding that on February 4, 2016 , the Ukrainian Prosecutor General’s Office, under the direction of Prosecutor General Viktor Shokin, announced the seizure of property from Ukrainian natural gas company Burisma Holdings’ founder...

It is also my understanding that on February 4, 2016 , Hunter Biden began “following” then-Deputy Secretary of State Tony Blinken, a longtime advisor to Vice President Joe Biden, on Twitter...

In addition, according to records obtained by media sources, on February 11, 18, and 19 of 2016 , Vice President Biden held a series of phone calls with Ukrainian President Petro Poroshenko regarding previous demands to dismiss Prosecutor General Shokin for alleged corruption. Another phone call between the two took place on March 22, 2016, just seven days before Prosecutor General Shokin was removed from office on March 29, 2016.