I get random calls everyday, and I suspect it is a systematic error on fido side. The reason why I believe so is that these numbers all have the same first six digits as my phone number. Sometimes there's no voice on the other side, sometimes the other people told me that they received a call from me. I suspect there's a bug on fido side that makes random calls between numbers having same prefix.
Welcome to the community!
Good suspicion! However, I think they are SPAM or SCAM calls from spammers/scammers using spoofed numbers. Unfortunately, there currently isn't much that any of the mobile providers can do to prevent them. Since the spammers/scammers use spoofed numbers, it is not possible to identify the true spammers' number. The numbers shown on caller ID do not belong to the spammers. They often belong to innocent, unsuspecting people, like yourself. That's why you've received calls from people thinking that you've called them. Your phone number showed on their caller-ID. There isn't much that can be done to prevent numbers from being spoofed. Even the RCMP are not immune to being spoofed (see here).
The spammers/scammers will tend to spoof phone numbers within their target range to make potential victims think the calls are coming from people they might know. Since your area code/prefix is for Fido (unless you ported from another provider), many of the calls will also appear to come from Fido phone numbers. It's called Neighbour spoofing (see here and here). In some instances, the spammers/scammers will use the recipients' own phone numbers to make the calls, called mirroring. Those are just the phone numbers the spammers/scammers chose to spoof. Unfortunately, there isn't much that can be done to prevent numbers from being spoofed.
The mobile providers have implemented Universal Call Blocking which is meant to block calls from malformed phone numbers. That said, I'm doubtful whether it will have much of an effect on the amount of SPAM or SCAM calls since many of them appear to have properly formed phone numbers. In addition, a new technology, STIR/SHAKEN (Secure Telephone Identity Revisited/Signature-based Handling of Asserted Information Using Tokens) is being adopted to further reduce the amount of nuisance calls (see here). However, I have my doubts as to whether those measures will reduce the amount of SPAM calls. My understanding is the STIR/SHAKEN will only identify possible SPAM calls and mark the calls as suspected SPAM.
Unfortunately, until the technology to unmask the true number of spammers/scammers is readily available (not simply the number shown on the caller ID), the only solution currently is to block the numbers on your phone. You should note that blocking the calls only prevents the calls from ringing your phone. It does not prevent the callers from leaving voicemail. There are (at least were) some apps which claimed to also prevent callers from leaving voicemail. They worked by answering and almost simultaneously ending the calls. While those apps do prevent calls from going to voicemail, the calls are also considered 'answered' and therefore count as airtime.
Hope this helps 😀