Have reviewed your install and the conditions are actually working properly. You are using static conditions on tabs on the registration page, which don't logically make sense.
For example the "About" tab is conditioned to only show to select usergroups. This condition 100% of the time will fail on registration view, because the users have no access to it. The interesting part is why this condition passes fine during the POST process. Have created a bug ticket to investigate that issue further.
forge.joomlapolis.com/issues/5728
For now you need to set the fields on that tab to not show on registration then disable the registration condition for that tab. The reason for this is the tab has no purpose rendering on registration, because it can't be used on registration due to the condition you are using.
In short if you're static conditioning a tab and it will never show on registration then ensure its fields are set to not show on registration to begin with as it's a usecase that doesn't make any sense to CB Conditional.