[ravagernl]

Originally Posted by F16Gaming Shouldn't that be "not PlayerFrame:IsMouseEnabled()" in order to toggle it?

Quoted for truth.

A more fitting solution would be to enable the mouse based on modifier state (ctrl/shift/alt keys):

local f = CreateFrame("Frame")
 
function f:Event = function()
    if InCombatLockdown() then return end
    PlayerFrame:EnableMouse(IsModifierKeyDown())
end
 
function f:Load()
     PlayerFrame:EnableMouse(false)
     self:UnregisterEvent("PLAYER_REGEN_ENABLED")
     self:RegisterEvent("MODIFIER_STATE_CHANGED")
     self:SetScript("OnEvent", f.Event)
     self.Load = nil
end
 
if InCombatLockDown() then
     f:RegisterEvent("PLAYER_REGEN_ENABLED")
     f:SetScript("OnEvent", f.Load)
else
     f:Load()
end

Untested, and probably has errors, but I think something like this would work