Old users on my website cant access it anymore after i changed server

Okey so my domain: lbslan.com was hosted on netlify before but now i have my own server. The domain is hosted at hostgator. Users that have used the website before i tranfered it can't access it anymore without clearing their browser cache or changing browser but i cant ask 100+ users change browser or clear cache.

I've tried to contact hostgators support about this issue but not gotten a real answer they just say that i and all the users have to clear their cache or change browsers.