Sorry to read this did not work out of the box for you. Sometimes there are graphics settings which can alter the default, and hopefully correct, behaviour of ROOT.
Could you share with us a reproducer for this plot, as well as the platform on which it was ran and the root version used?
Thanks. The script is not really a reproducer, since it depends on many other libraries we do not have access to: can you make it a standalone reproducer?
The 1st label of the top pad is hidden by the bottom pad. This doesn’t not happen when use TRatioPlot. I guess your script isn’t. TRatioPlot uses ChangeLabel to erase the first label of the top pad. You can do the same. You can see an example here: ROOT: TGaxis Class Reference