Started Project at 0'-0" - Topo surface is 99m too high even after moving base point

[3dway]

Hi all.

I've been chasing ghosts here in terms of finding an answer for this.
Every time I find a new method, they all seem to just be different ways to the same thing.

I started modelling at 0'-0" I have a mostly done house. I want to do a topo surface based on the newly arrived survey data. This is the normal course of my projects. The survey work comes in well after design is underway.

I know my new finished floor number will be about 99.55m above sea level.
I can switch my levels to report shared elevations, but all of the solutions just seem to add a number to 0'0" to get it to report a value. No real change happens.

My problem is, if I make a topo surface and type in 99m above sea level for the points (for simplicity's sake lets say they're all the same elevation).

So whether I set my project basepoint, or use manage and specify an elevation on my 0'-0" level, or whatever, the topo surface still sits 99m higher than I want it. How do I enter topo points on using the shared elevation?

As clarification, I should note that after changing the project base point to be finished floor at 99m. The level head reports the finished floor level of 99m (actually in feet, but that's the next problem, not right now). If I select an elevation point on the topo surface it say's it's absolute elevation is 99m, but it's 99m above my finished floor which itself is 99m. the topo point should be reporting 99m+99m=198m.

[3dway]

Tried making a sea level "level".
Even associating the topo surface with my new sea level doesn't change the "elevation" of the points.

[3dway]

OK, so not even that worked.
Probably time to RTFM