Flying via Lisbon

We go to the Cape Verdes quite often, and on the last two occasions we have missed connecting flights coming back from Sal to Lisbon. As we live in London it's not too much of a problem but a bore. When you get re-routed to Gatwick instead of Heathrow you wonder whether your luggage is going to travel with you or independently to the airport of your choice. So far we haven't had problems with luggage. But the flight connections in Lisbon are very tight and it's easy to miss the connection and on the outward journey you get to spend a day in Lisbon instead of in the Cape Verdes.