Do you have RIN displayed? Tools > File Options > Number to display after name
Look carefully at the couples with multiple spouses of the same name. Do the duplicates have the same or different RIN?
If RINs are not the same, then you probably need to do a manual merge.
If RINs are the same, do you have duplicate marriage facts for the couple?
If you have duplicate marriage facts with the same date and place, then delete one (or more) duplicates. Make sure to copy non-duplicated sources to the marriage record you are keeping.
If you have duplicate marriages with different dates, is one an error, or did the couple actually marry twice (maybe with intervening divorce, or maybe as a re-commitment on an important anniversary) ? Are there two marriage facts with same date but different place?
I have a custom fact that I use to preserve documentation, while eliminating confusion about which marriage is the primary (most likely to be correct) fact:
Name: Marriage (Alternate)
Abbrev: Marriage (Alt)
Fact type: Family
Publish online / Create HTML: Yes
Group sheets: Yes
Narrative reports: Yes
Individual summary: Yes
[Couple] <#Couple#was|were> married (alternate fact info)< [Date]>< [PlaceDetails]>< [Place]>, [Person:given] was <[Person:Age:plain]> years old and [Spouse:given]< was [Spouse:Age:plain]>. <?[Desc]|[Couple:Caps:NoCycle] were [Desc].|>.