The WALLCLOCKTIME object was changed in v16. Prior to v16 the structure was different and the software warned you whenever you upgraded a pre v16 project.
I ran into some issues with the Ramp/Soak Function Block not updating properly. I never really got that figured out. Once I deleted it and recreated it it would work fine. That was going from v17 to v18. Now when I upgrade a similar project from v17 to v19 it works without issue. Might have been a logic issue, not sure.
OG