We found server get Mac's IP slow cause mac join domain fail

we setup domain account in Server.App, around 100 end users. we found end user log in Mac by domain ID fail always. since we checked, we know server get Mac IP slow, if Mac lock out, server will release Mac's IP. so since user back, server do not know MAC, and MAC can't get Authe information from server, so log in fail. but if we are waiting for 1 mins, then we can log in.

so anyone face same problem? and how to resolve it?

thank you

Calvin