If LDB mode is pikced without locking up window with canfybars, then header is always shown on sceen because legionTimerDB.lock never become true, is not possible to lock it when LDB mode is ticked in options

	if legionTimerDB.lock then
		f:EnableMouse(false)
		f.bg:Hide()
		f.header:Hide()
	end

Here is what I did:
Switch to LDB
Switch back to Bar
Untick "lock"
Switch to LDB

It is correctly locked, am I missing a step?

Closing, cannot reproduce. Recommending BugSack if you wish to further debug it, as I suspect you may be encountering an error.

Not exactly. Here are two pictures how it behave at my client. 1st picture show before I pick data-broker and 2nd how it looks on screen and when I use /lit ro see settings.

I found may be reason where problem is. I had LUA variables in LegionInvasionTimer.lua from 1st release, when I did erase stored LUA variables it did with same steps to reproduce next two pictures.

After I did purge LegionInvasionTimer.lua in WTF folder.

As you can see green title with "LegionInvasionTimer" is gone as should be. I found that in my old LUA variables was really ["lock"] = false

Having the old settings wouldn't make any difference. It was always called "lock", it hasn't changed since last year. The code specifically sets lock to true and then reloads your UI. I have no clue why lock wasn't being set to true for you when the option was changed, or why suddenly it now is. Maybe you had some read-only problem with the settings.

Not seeing the problem here. As soon as you choose LDB mode the option is set to locked.
https://github.com/funkydude/LegionInvasionTimer/blob/master/Options/Options.lua#L376

Cannot reproduce. Working perfectly fine here. As soon as I swap from bar to data broker mode, it's locked.

You can reproduce it easy. Switch back to candy bar mode, untick locked. Then selcet LDB mode mode. And you will see what happens, there will be header and you can't tick locked because option is greyed.

Solution is when you code auto lock in moment when LDB mode is selected.