Presumably, the Russian military is waging electronic warfare in northern Norway
Because of this, flying over the Norwegian region of Finnmark, planes lose contact with the satellite navigation system.
Such attacks have been ongoing since 2017, but this year they intensified. Over the past three months, there have been 21 days of disruption. The communication did not work for the same number of days throughout 2021.
The Norwegian Communications Service attributes this to the full-scale Russian invasion of Ukraine and Russia's desire to demonstrate its strength to Norway.