If you /reload shortly before the "Seconds" timer would increment, the first rough time update skips a second, so when the next second starts and the thorough time update happens, the same second gets repeated and it's in sync again.
Potential cause:
The scheduled "increment" functions probably don't get cleared, as the same phenomenon can be observed when minutes are supposed to increment as well. There, it subtracts 60 from the seconds timer, indicating that it's not a problem with reading the command block's values.
Bug:
If you /reload shortly before the "Seconds" timer would increment, the first rough time update skips a second, so when the next second starts and the thorough time update happens, the same second gets repeated and it's in sync again.
Potential cause:
The scheduled "increment" functions probably don't get cleared, as the same phenomenon can be observed when minutes are supposed to increment as well. There, it subtracts 60 from the seconds timer, indicating that it's not a problem with reading the command block's values.
https://github.com/BluesCrew/TimeLib/assets/77808092/30cc0ea4-9b87-456e-9994-b808241969a2