47 minutes ago, ZMR said:I hope someone can help me resolve these issues.
due to some specific differences in Operating Systems, Theme applications, modules, version to version, most shops are not so similar.
What all shops have in common is the database. Go to your backend and delete all those customers which are from years back.
You should save their emails though.
You server could also be the issue slowing down, the differences from hdd vs ssd are dramatic.