This is the PI Interface question. It will be dealt with by OSIsoft Techsupport team. Your issue has been transferred, and they will contact you about this. However, could you please check you tag setting on exception and compression? The missing data might be filtered by these 2 calculation.
Until now I have not been contacted by OSIsoft Techsupport team, but I would like to thank you for your support. However I checked and no tags have exception and compression actived