Just checked
Forgehammer of Gond
vs
Duergar Mercenary's Steeled Cross-pein Hammer +1
and the percent in Focus has changed from 47% to 46%.
But the bug isn't just that.
Why 1189/1450 = 0.82 is shown as 47% or 46% at all?
For comparison, the number 72% in Proficiency is shown correctly since 1044/1450.0 = 0.72.
Comments
If you has minimum required focus, you have 5%.
(1189 - 1000) / (1450 - 1000) + 0.05 = 0.47 = 47%
I can't explain the 47% and 46% difference. Most likely some kind of rounding somewhere.