I saw a report that the main swimming pool was closed because of a 'technical issue', which probably means the filtering or pumping systems are not functioning.
Going on the first cruise after a shipyard overhaul is always going to be a roll of the dice. Some may think the ship ought to be 100% when cleared to leave the yards, but given that any large vessel is an extremely complex machine it is impossible for it to ever be problem-free. However, it is the degree of problems that makes the difference. A pool not working is a minor issue. Basic hotel services such as stateroom water are significant. There is no excuse for all the cabins to not have both hot and cold water. That is a basic check-off on any shipyard punchlist.