Numbers lock / unlock table or chart AND Lock to protect formulas/table contents

Hi

I have many charts that get moved around by the hide/unhide rows that I have to use on my current spreadsheet (sometimes I need to refer to the hidden rows containing formulas).

What I really don't get is how difficult it is to assess what exactly Numbers is doing when using Lock / Unlock because so far executing a simple notion like fixing a chart to a cell area within a spreadsheet using Numbers has been a real struggle?

I can open a new spreadsheet, place a chart in it just where I want it, then hit lock but then if I tap outside of the table I'm presented with this for some reason?: (I had to use cmd - z to remedy that format menu)...

If I hit lock and then tap anywhere within the table and then back on the chart, I see on the right it's saying "lock" and "unlock" (both in white) as if I didn't just lock the chart? Its confusing...

Even more bizarrely there are times when I have literally ended up moving the whole huge spreadsheet in its entirety (from it's top left location) by placing the cursor on say the one locked chart I'm experimenting with, whilst all the other unlocked charts all stay in the exact same original position which then looks a mess? (Cue: cmd - z) This seems to happen when I first lock a chart, then tap in the table elsewhere then the chart where Im given both options to lock / unlock but when I hit unlock the whole entire table moves leaving all the other unlocked charts in the wrong position.

What am I missing?

Also can I secure certain parts of the the sheet so that its intellectual property (formulas/tables) are hidden from people I sell the sheets too?

Cheers.