Torrentio has been restricted depending on the country that you're VPN-ing from. Even without a debrid, just VPN, torrentio on stremio was rarely working.
Ended up using TorrentsDB, a torrentio alternative add-on that uses the same scraped data as torrentio but was more readily available.
https://stremio-addons.net/addons/torrentsdb
I don't know why you're facing those issues with TorBox. I signed up with a VPN on and no issues. People tend to prefer TorBox specifically because they don't care about your IP address and they accept multiple accesses to the same login. Are you using a bank card for payment?
Worst case, try signing up for TorBox from a public wifi or similar.
Also with TorBox, they're pretty private already and you don't necessarily have to use a VPN. But you still can if that's what you want.