I did some looking into this subject after Veritassium posted a video regarding cosmic rays changing the election result in Belgium some time ago[1]. But looking further into the issue, it seemed that there was (and is) scepticism regarding cosmic rays being the actual reason for the miscount. [2][3]

1. https://www.youtube.com/watch?v=AaZ_RSt0KP8 2. https://web.archive.org/web/20070927185155/http://wiki.ael.b... 3. https://blog.paco.to/2017/cosmic-rays-did-not-change-electio...