It's 48 months from your most recent Sapphire bonus, not from when you opened or closed the account. The 48 month period applies only to Sapphire branded cards. You can still earn UR bonuses on INK Preferred, INK Unlimited, INK Cash, Freedom, Freedom Unlimited on a 24 month cycle, and it does not sound as if you have held all three of the INK cards.
So Chase considers the CSR and the CSP to be the same product? It has been about 4 years since I 'earned' the CSP bonus and 20 months for the CSR.
Does the product need to be closed a specific amount of time before one can be reapply for it or can I just cancel the card the day before I want to reapply (as long as it has been 48 months since the bonus was received)?