In Calc, there is a feature called 'Auto Correction'. It maintains a list of text entries for each column and when you start to type a new entry, it uses the partial entry to get a match from the list. In OO, you could scroll forward through the list using TAB and scroll backwards using Shft-TAB. That does not work in LibreOffice even though the docs say it should. TAB and Shft-TAB do the same thing as the Right-Arrow and Left-Arrow keys. To scroll through the list requires Ctrl-TAB and Shft-Ctrl-TAB.
I hate these kind of changes. I still press the TAB key to scroll through the list even though I know it doesn't work anymore because it has become 'automatic behavior' and it will take some time to unlearn it. In the meantime, I am less productive.