REMD demux replica_temp.xvg File Issue After 1us Simulation

GROMACS version: 2016.5
GROMACS modification: No

Hi, users,
After running REMD or REST for 1us and using the demux command to generate replica_temp.xvg and replica_index.xvg, I found an issue with the time column in the xvg files. First, the whole time value can not be generated (it shows 1.00001e+6 rather than the exact time). Second, there is supposed to be 10 “1.00001e+6” even without precise time (0-9), but there is only 9 for “1.00001e+6” and 11 “1.00002e+6” and so on so forth, although the sum up seems to be correct. The third issue is that the xvg file starts with 0 and 6 “1e+06” and ends with 5 “1.2e+06”, where my simulation is supposed to end at 1200ns. I wonder if anyone has encountered the same issue before. It confuses me that I am not sure the way I concatenate the xvg files is correct. Since I cannot upload the example files, I have copied and pasted some part of the xvg file here. Thanks in advance!

0 0 1 2 3 4 5 6 7 8 9
1e+06 0 2 1 3 4 5 6 7 8 9
1e+06 0 2 1 3 4 5 7 6 8 9
1e+06 0 2 1 3 4 5 7 6 8 9
1e+06 1 3 0 2 4 5 7 6 8 9
1e+06 2 3 0 1 4 5 7 6 8 9
1e+06 3 2 0 1 4 5 6 7 8 9
1.00001e+06 3 1 0 2 4 5 6 8 7 9
1.00001e+06 3 1 0 2 4 5 6 9 7 8
1.00001e+06 3 2 0 1 4 5 6 9 7 8
1.00001e+06 3 2 0 1 4 5 7 9 6 8
1.00001e+06 3 2 0 1 4 5 7 9 6 8
1.00001e+06 2 3 0 1 4 5 7 8 6 9
1.00001e+06 2 4 0 1 3 5 8 7 6 9
1.00001e+06 2 4 1 0 3 5 9 6 7 8
1.00001e+06 2 3 1 0 4 5 9 6 7 8
1.00002e+06 3 2 0 1 4 5 8 6 7 9
1.00002e+06 3 2 0 1 4 5 8 6 7 9
1.00002e+06 2 3 1 0 5 4 8 6 7 9
1.00002e+06 2 4 1 0 5 3 8 6 7 9
1.00002e+06 2 5 0 1 4 3 9 6 7 8
1.00002e+06 2 5 0 1 3 4 9 6 7 8
1.00002e+06 2 5 0 1 3 4 9 6 7 8
1.00002e+06 2 5 0 1 3 4 9 6 7 8
1.00002e+06 2 5 1 0 3 4 8 6 7 9
1.00002e+06 2 5 1 0 4 3 8 6 7 9
1.00002e+06 2 4 1 0 5 3 8 7 6 9

Regards,
Peiyin