After the Bitcoin Cash & Bitcoin SV fork, Bitcoin Cash is happy to be "ahead" of Bitcoin SV, but how is this possible? aren't blocks supposed to be mined constantly every 10 min?
Solutions to the proof of work are found randomly (by guessing until you find a valid block hash). So, the difficulty is adjusted in order to set an average block time of 10 minutes, but that is not always how it happens in practice.
Also, when the total network hashpower grows before the difficulty is recalculated (which happens every 2 weeks on Bitcoin), blocks can (and are) solved at a faster rate than every 10 minutes. The same applies in reverse, less hashpower will cause block times to increase above 10 minutes (until the next difficulty retargeting).