I'm noticing a significant difference in time logged for each power level when reviewing data SRMwin and WKO+. The power training zones contain the same wattage range values and date ranges in SRMwin and WKO+. Today SRMwin showed L1=0:20, L2=1:29, L3=0:07. Same file imported into WKO+ shows L1=0:28, L2=1:17, L3=0:11. Total time is the same.
After changing the slope on one of my PCVs, I found that I was "missing time" which led to discrepancies in time between SRMWin and CP. I reset the PCV using SRMWin and the problem went away. I don't know if you're having the same problem but it could explain what you're experiencing.