Question : why changes to AD is being undo by other DC

I have 4 DC on two sites, (with DFS setup), I thought if I create a local and global security groups and add member to Global group and give permission to local group and add global to local group then this will be replicated to other DC and as result the users who access the DFS will get permission to the folders in in the dfs. however I notived the grops are being removed by other DC when I forced the replications.
Am I missing something here?
should I create the Groups from the 1st domain in frost?

Answer : why changes to AD is being undo by other DC

unless there is a desperate need to have more than one CPU, don't allocate the additional CPU as it will have a negative effect on performance.

my advise would be to monitor the performance of each server and then tweak CPU settings accordingly.