I think I saw somewhere that this doesn't apply anymore. It is always 5 years back from the day you submit the application (Given you can apply for renewal after you card expires)
I do not know what you are talking about. Nothing has changed. It has nothing to do with the card.
It is exactly as I wrote;
-first five years, it is from date of landing to the fifth year anniversary;
-after that, five years looking back from any date of examination.*
*Which you should calculate as day of submission in case of eg a PR card renewal, as that's what they require in the form I believe, but in actual fact for IRCC, they must calculate as at the day they actually examine your file.