You may be onto something here.
Both jobs were imported from older versions of FCP to 6.0.3.
The difference in the timelines might be due to each originating in different versions of old FCP in the last three or four years.
I have found a way around it by making sure my first nest is the longest of the versions and then just using the shorter VO and some slug to make the duration match the longest in other versions. No ripple can happen that way.
A convoluted workaround but still saving a ton of time.