Extra daily high/low data

I have 2 PCs networked, running WD on both, client is set to receive clientraw file from server & use data & logfiles on mapped drive on the server. Has been working perfectly but now when I view daily high/low data on the client the max temp for 31/12 appears as max temp for 1/1, all other data is correct. Can’t work it out as it’s correct on the main PC & they are both supposedly reading the same data files. Not a big problem, just very annoying.