"Plots yield 10% increased crop per adjacent plot being farmed" NOT WORKING

Like in the title, 11th upgrade of farming is not working.
When I select wheat in the first plot it has the same production per hour even if I put wheat in an adjacent fields.

Additionaly, production gets lower when I put wheat in last, 6th plot.
It's like "5% increase crop yield per different crop being farmed" counts "nothing" as different crop and lowers a final result.

But then maybe 10% bonus from farmed adjacent plots is counted even with empty plots, so it is applied permanently and we just don't see this?

Looks to be counting "nothing" as a crop. Reviving this post as it's still happening.