I have a 4G Voor Thuis subscription.
Occasionally, I am blocked from accessing certain websites. Interestingly enough, Odido's website is one of them. Initially, I thought it was a DNS problem, but that turned out not to be the case.
I removed the SIM card from the modem and placed it into a phone, but the issue persisted. I think this can exclude a problem related with my equipment.
Calling Odido's help desk didn't resolve the issue. The employee refused to acknowledge that the problem wasn't with the modem and asked me to go to an Odido shop to have it checked. However, the shop turned me away because they don't check routers.