How do I get appointments to stop overlapping?

[wellnesshaven24]

Some of my services include add-ons that you can book separately, like sauna and cold plunge.  Somehow these services are now lapping where 2 people are getting booked for the sauna at the same time. I do NOT need this to happen, this is a private time. 

[Minion]

HI @wellnesshaven24 

Do you mind sharing a screen shot of your settings for each service?