Repeating/Duplicate comments problem

A number of my guest visitors are complaining that they are seeing multiple copies of old comments that they posted, showing up in the comment list. I do not have user logins enabled so all comments are guest comments. One visitor said they are showing up just before the Load More Comment button. I am not seeing the repeats on my end for most of the visitors complaining but I have seen up to 5 repeats of other visitor comments. I checked the database and there is only one comment even though it shows up multiple times in the comment list. If I disable wpDiscuz, the default wordpress comment list shows only one comment. I'm not sure if it is of any significance but I have wordpress cookies disabled. I'm not sure why a comment will show up multiple times even though it only exists once in the DB and why the repeats are not being seen by all users.

Any assistance will be greatly appreciated.