From geopolitical point of view it made perfect sense, had soviets reached western Norway they would have finally achieved centuries old Russian dream of having warm water port and undisturbed access to oceans.
But soviets didn't do much to advance swiftly there and abandoned captured territory in Finnmark easily, why ?
Mostly because it was an unnecessary expenditure of resources. Murmansk is already open year round and you wouldn't really gain much by seizing one of the Norwegian ports like Narvik or Bergen. The road networks are terrible that far up into Norway and the terrain is atrocious for offensive action. They would have to divert large quantities of men and material for little strategic or tactical gain when they were needed elsewhere. More pointedly it is unlikely that the other Allies let Russia keep Norwegian territory at the end of the war particularly someplace like Bergen. Would the Russians have risked such political backlash for a port that didn't really change anything on a strategic level. Seizing control of Norwegian ports is not strategically necessary so why waste men and material to achieve it.