IP Geolocation issue

Hello,

I am a junior Network Analyst for an ISP in Canada/Quebec and a few of our customers can’t access certain websites because of a geolocalisation issue. For example, customer A can’t access a certain Canadian website because the website thinks he’s in the US, customer B can’t access his company Microsoft Teams...

The IP block my company uses for customers is correctly registered with ARIN, but some IPs shows up in the US on some geo IPs web databases. I am not sure how to solve that issue. Any kind of tip/advice is welcomed. thank you in advance

Edit I've already contacted the providers on this list https://thebrotherswisp.com/