Hello monymony,
attached the output of your Live-txt file (above) and mine (below). For that we use both a VantagePro and WeatherCat and Meteotemplate there should be the same output of the files? Maybe Stu can shed some light on this mystery. My UV reading is much earlier in the row than yours.
{"U":1507629416,"B":224,"W":0,"G":0,"H":95,"T":19.300000000000000710542735760100185871124267578125,"HIN":54,"TIN":30.10000000000000142108547152020037174224853515625,"RR":0,"R":0,"P":1016.6200000000000045474735088646411895751953125,"S":1742,"LW4":0,"SW":"WeatherCatV2.42B15","UTime":1507629416,"BTime":1507629416,"WTime":1507629416,"GTime":1507629416,"HTime":1507629416,"TTime":1507629416,"HINTime":1507629416,"TINTime":1507629416,"RRTime":1507629416,"RTime":1507629416,"PTime":1507629416,"STime":1507629416,"LW4Time":1507629416,"SWTime":1507629416,"UV":16,"UVTime":1507629416,"D":18.5,"DTime":1507629416,"A":22.300000000000000710542735760100185871124267578125,"ATime":1507629416}
{"U":1507629555,"B":101,"W":9.7,"G":9.7,"H":54,"T":12.3,"HIN":40,"TIN":21.9,"RR":0,"R":0,"P":1018.11,"S":566,"UV":2.4,"T1":22.8,"LW4":0,"SW":"WeatherCatV3.00B1622","UTime":1507629555,"BTime":1507629555,"WTime":1507629555,"GTime":1507629555,"HTime":1507629555,"TTime":1507629555,"HINTime":1507629555,"TINTime":1507629555,"RRTime":1507629555,"RTime":1507629555,"PTime":1507629555,"STime":1507629555,"UVTime":1507629555,"T1Time":1507629555,"LW4Time":1507629555,"SWTime":1507629555,"D":3.2,"DTime":1507629555,"A":9,"ATime":1507629555}