Overseer % win nerf

I've seen a change in the percentage chance to win an overseer mission since the May patch, on a couple of quests.
I tend to do the 12 hour quests to get the fragment for collections. My go to quest is Dark Deeds, which was 91% but now its down to 90%. No agents were questing or incapacitated at the time. A few others have gone from 89% to 88% and I think some have gone from 88% to 87% but that's anecdotal, I need to test a bit more.

Are actual win % changes or just the numbers it posts?

Actual Stats from overseer stats tab.

130 quests completed.
31 critical success
99 success
0 Failures
0 Critical Failures.

I have 249 agents ready , 28 questing, and 5 incapacitated.

I guess the real question is. "What does the success percentage actually represent?"

Win % changes have changed. My understanding is the higher the % chance, the more chance you have of winning, and maybe having a critical success?

Just a guess, but maybe something has changed in how they round the percentage value after the success calculation. It's likely that the success calculation is not a nice number like 90 or 91. The actual calculated percentage might be a number like .9068138. But since they don't want to show the value 90.68138% in the Overseer window, they round it to 91 or 90. If something has changed in how they convert the calculated percentage to a nice number for display, then that might explain the change.

Keep an eye on your actual success rate in terms of how many quests succeed or fail. The value shown in Overseer might just be a cleaned up value for the player's benefit. Behind the scenes, they should be using the actual percent from the math of calculating the chance of success.

I wouldn't worry about it, exp display went down by .001%, and some of the recipe success aren't displaying properly. Wait until everything is converted then check again, something probably got hit in the backend that will straighten out in the end.

It is probably this with rounding, probably being truncated or something now instead of rounded

How do some people have 0 Failures/0 Crit Failures????

Good luck? Or more likely, stats being wiped. Mine have been wiped several times. Why they were wiped, I have no idea.