Table Locking

I had an existing drawing with a table I had to use.

So I formated it how I wanted it and then did Format Lock.

But then randomly different cells would change format, different text colour, height etc. while I was filling it in.

Very annoying at the time.

The table style might have been different to what I changed them to but once I lock it they shouldnt randomly revert back should they?

Is there a way to lock the tables formating which actually locks all the cells. Or should I have just started again rather than trying to fix what was already there?