Of course there are a billion examples, the UK is literally the best one because even today the UK exerts sovereign power over 50+ countries. Just 100 years ago the UK held sovereign power for over 30% of the world.
Ukraine is a fully recognised country whereas Palestine is not, it's very different, I mean christ Ukraine is even recognised by Russia and Russia knew itself that it was annexing territory. In the eyes of the world Ukraine was territorially invaded and the eastern regions and Crimean Peninsula today are annexed by Russia.
Look at a map though and compare this to Ukraine, what or where is Palestine? Palestine does not exist as a state, the borders of the Palestinian areas were drawn on agreements and not by the ratification of an independent state. The reason that ratification never occurred is because the Palestinians oppose the creation of Israel and still lay claim to all land including the entirety of Israel. It's for this reason that the west does not recognise Palestine.
Palestine should be recognised of course but that requires compromise and acceptance of Israel which unfortunately will never happen, at least it won't with the Hamas regime.