We had the same issues with trying to enter. The first time we stopped (11am) the lady was in her apartment across the way saying something in Portuguese and then went inside and closed her window. We came back after visiting the other sights in town. The sign was up for the entry but the doors were locked. This time we made sure we came after 2. We waited 15-25 minutes before the same lady came strolling from a different direction (I tried calling the # on FB & google with no success). We were there for 5-10 minutes. The ceiling is pretty cool and unique. But,not sure it's worth the hassle, unless more accurate hours are posted. It's a pretty church, but may not be worth the drive from Porto (especially if a visit is also planned for Braga).