extruder fan offset : Fan control not working as expected

[A13xund3r]

What happened?

Top solid infill is cooled when it is disabled in setting, whole first layer is cooled when it is disabled, bridges and overhangs are not cooled when set to be cooled. Also "Enable fan if layer print time is below" when set to less than 6 all print is getting fan at 95%, for more than 5 only partial cooling happen.
It seems all fan logic is reversed.
Settings:

Top view:

Bottom view:

Project file & How to reproduce

Temperature calibration.zip

Version

2.5.59.8

Operating system

Windows 7

Printer model

Modified Zonestar Z9 with Marlin 2

[A13xund3r]

It was "extruder fan offset" set to 95. Changed to 0 and it is almost as expected. External perimeter which is part of bridge is using perimeter fan setting, extruder fan offset is ruining fan control if not 0, seems to have trouble if result of offset + current element setting is higher than 100%.