WoWInterface - Minimap button highlight dragging

When I drag the minimap button along the edge, it remains the halo of highlight as you can see in the picture

This is the code:

XML code (I used nopaste service to avoid wall text)

https://nopaste.me/view/2875c949

Lua code

Lua Code:

function MyMod:onMinimapButtonClick(button)
    if (button == "LeftButton") then
        print("foo")
    end
    if (button == "RightButton") then
        print("bar")
    end
end
 
MyMod.mmdp = 45 -- MyMod minimap button default position
 
function MyMod_MinimapButton_Reposition()
    MyMod_MinimapButton:SetPoint("TOPLEFT","Minimap","TOPLEFT",52-(80*cos(MyMod.mmdp)),(80*sin(MyMod.mmdp))-52)
end
 
function MyMod:onMinimapButtonUpdate()
 
    local xpos,ypos = GetCursorPosition()
    local xmin,ymin = Minimap:GetLeft(), Minimap:GetBottom()
 
    xpos = xmin-xpos/UIParent:GetScale()+70 -- get coordinates as differences from the center of the minimap
    ypos = ypos/UIParent:GetScale()-ymin-70
 
    MyMod.mmdp = math.deg(math.atan2(ypos,xpos)) -- save the degrees we are relative to the minimap center
    MyMod_MinimapButton_Reposition() -- move the button
end

Can you help me?