There's only one thing that's unusual about an alleged "shortage" of SK (and Lapua) .22LR ammo, and it has nothing to do with the Russians. SK/Lapua has said the war in Ukraine doesn't affect .22LR ammo production.
It has more to do with Americans and the extraordinary popularity and growth of .22LR PRS-style shooting. The demand for .22LR match-type ammos has grown tremendously. Unfortunately production output hasn't been able to keep up with demand. Even in Canada the enthusiasm for .22LR PRS has increased enormously and it's no longer possible to count on suppliers being able to maintain stocks of ammos like SK from one shipment to the next.