When you are manoeuvring under mainsail only, don’t expect the boat to sail properly with the sheet pinned hard in. This is a requirement when a genoa is set to stop the main backwinding, but as soon as the jib has gone, the main is cutting clear air which is no longer bent forward by the headsail.
Close-hauled under main only, steer about 45 degrees from the true wind, then trim the main to the breeze as though you were reaching. The boat will end up pointing higher and sailing faster. And she won’t be going sideways.