The sanctions on Russia are because of their (covert) invasion of the Ukraine. They have to settle that conflict to justify sanctions relief.
There was nothing covert about the Russian invasion of Ukraine. Obama & Merkel had plenty of intel showing Russians Army units moving across the border and just chose to ignore it.
“There was nothing covert about the Russian invasion of Ukraine.”
Russia officially denied it, and sent many of their active military into the fight in the Ukraine in civilian clothes, and under the flag of militias of the Russian-speaking minority within the Ukraine.
But yeah, Obama and Merkel knew. More and more damning information came out over time, so that the Russian public began to know as well - but it is still risky in Russia to be vocal about it.