[Xrystal]

Well my test addon doesn't save it .. but, testing bugsack and it does. So something in its code must be saving it in some form.

edit: Okay figured it out ..

Files Changed:
TestAddonSettings.toc
File changed to have 2 saved variable tables, one for the addon data and one for the minimap icon data

## Interface: 100207
## Title: TestAddonSettings
## Author: Xrystal (c) 2024  All Rights Reserved
## Version: 0.0.1.001
## Notes: Testing Addon Settings
## RequiredDeps: 
## OptionalDeps: 
## DefaultState: Enabled
## LoadOnDemand: 0
## SavedVariables: TestAddonSettingsData, TestAddonSettingsData_MinimapIcon
## SavedVariablesPerCharacter: 
 
SettingsPanel.lua
MinimapButton.lua
Code.lua

MinimapButton.lua
-- Redesigned file to match bugsacks segmented approach ( in case that was the solution ). It looks tidier though so kept it
-- Made sure Saved Variable tables were initialised with default values
-- MinimapButton's saved variable data was put in its own table, not a sub table same as bugsack
-- The MinimapButton was also initialised on player login - of course this would be when the saved variables would have been loaded up - this might have been all we needed to do.

local addonName, addon = ...
 
-- Main Addon SavedVariable Table
TestAddonSettingsData = TestAddonSettingsData or {}
 
-- Minimap Icon SavedVariable Table
TestAddonSettingsData_MinimapIcon = TestAddonSettingsData_MinimapIcon or {}
 
-- Initialise Minimap Icon values
-- Use settings panel to allow player to change these 
-- When you move the minimap icon around the minimap the ldb library updates the respective MinimapIcon saved variable table
-- The MinimapIcon Saved Variable Data has to be its own table, not a sub table
TestAddonSettingsData_MinimapIcon.hide = false
TestAddonSettingsData_MinimapIcon.lock = false            
TestAddonSettingsData_MinimapIcon.minimapPos = 120
TestAddonSettingsData_MinimapIcon.radius = 80
 
-- Make sure library exists
local ldb = LibStub:GetLibrary("LibDataBroker-1.1", true)
if not ldb then return end
 
-- Create Plugin
local plugin = ldb:NewDataObject(addonName, {
    type = "data source",
    text = addonName,
    icon = "Interface\\BUTTONS\\UI-GroupLoot-Dice-Up", -- Replace with path to your icon
})
 
-- Handle OnClick functionality
function plugin.OnClick(self, button)
    if button == "LeftButton" then
        Settings.OpenToCategory(addon.category:GetID()) -- Open or close the options panel
    end
end
 
-- Handle OnTooltipShow functionality
function plugin.OnTooltipShow(tooltip)
    tooltip:SetText(addonName)
    tooltip:AddLine("Click to open options")
    tooltip:Show()
end
    
-- Initialise Minimap Icon on Player Login    
local f = CreateFrame("Frame")
f:SetScript("OnEvent", function()
    local icon = LibStub("LibDBIcon-1.0", true)
    if not icon then return end
    icon:Register(addonName, plugin, TestAddonSettingsData_MinimapIcon)
end)
f:RegisterEvent("PLAYER_LOGIN")

Anyway, after these changes, the minimap button now retains its location successfully.