can an employer continue to pay contributions to my rrsp through payroll if i reached the annual rrsp contribution maximum?
No, they can't. The contribution limit includes your contribution and your employer contribution. Check this link for more FAQs on this subject:
https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/rrsps-related-plans/contributing-a-rrsp-prpp/contributions-affect-your-rrsp-prpp-deduction-limit.html#whcncntrbte
I hope this was helpful