"jobill -i file" will not be executed beause the current pathname will be added in front of the specified pathname

Yes I know - jobkill is used very rarely. However, if used at all, it should work as expected.

Please have a look at the following screenshot - it speaks for itself

Of course it will run, if you just specify a filename which is stored in the current directory.

I have verified this for NW/Windows versions 19.6.0.0, 19.6.0.2 & 19.6.0.3.

It might properly run on a Linux host but I have not verified this.