Tooltip and Constants

[VincentSDSH]

I'm seeing a very strange issue with tooltip location and it doesn't seem to be an addon that's doing it.

Background:
In FrameXML/ContainerFrame.lua are the following lines:

CONTAINER_OFFSET_Y = 70;
CONTAINER_OFFSET_X = 0;
CONTAINER_SCALE = 0.75;

In FrameXML/GameTooltip.lua is the following:

function GameTooltip_SetDefaultAnchor(tooltip, parent)
    tooltip:SetOwner(parent, "ANCHOR_NONE");
    tooltip:SetPoint("BOTTOMRIGHT", "UIParent", "BOTTOMRIGHT", -CONTAINER_OFFSET_X - 13, CONTAINER_OFFSET_Y);
    tooltip.default = 1;
end

This should position the tooltip point at -13, 70...but it never seems to be.

This is where it gets weird.

If I dump these constants, they aren't 0 and 70 respectively. In fact they are different for different characters (with some duplicates that seem to be isolated to server but I have low confidence that means anything). They are always near that area but a difference of 30pixels is still odd since it shouldn't change at all.

I've checked every addon and library and none change this constant -- this happens in the base UI with no addons.

I thought I'd just set them back to the defaults and be done with it but they change at least twice during load, so change after the end of my :OnEnable() function. I got cleaver and delayed resetting them for 2 seconds and that seemed to work but within a minute they were changed again.

This behavior also happens in the base UI, setting and dumping the not-quite-constants via /script and /dump commands.

I'm wondering if there is something, maybe at the C level, that can modify those under some condition or other, or some scaling thing that affects them (I didn't find any in the Lua but maybe I missed it).

This is only a problem in one tiny area of my UI and it's easily worked-around by resetting the constants back to default before I do what I need to do so this is more informational than anything.