Hi @ironypirate welcome to the community,
An other customer had the same issue as you (https://community.sunrise.ch/t5/Internet-mit-Modem/Was-bedeutet-Partial-Service-US-only/td-p/84074). It seems it’s a problem with the upstream channels. The single solution is to call the UPC’s hotline : 0800 66 88 66. The support will solve that. 
Best regards,
Michael