Hi ALL, When I adjust the system time with data command, chronyd just logged: Jan 2 13:56:40 localhost chronyd[124497]: Backward time jump detected! Jan 2 13:56:40 localhost chronyd[124497]: Can't synchronise: no selectable sources I'm sure the source is well connected, and after several minutes chronyd can synchronize the time correctly with the source, but why chronyd logged 'Can't synchronise: no selectable sources' if I manually adjust my system time with data command every time?