Job instance cannot read .config file

I recently started to use this awesome piece of software, really good work.
Unfortunately I came across small issue I can’t solve by myself.

The problem is that an instance of class which runs a task of a job cannot access .config file.
The weird thing is, that the setting of GlobalConfiguration.Configuration.UseSqlServerStorage("SQLserverConnString"); can access data in .config file with no problems, but then a new instance of a class running the job can’t get some other setting.
Beside Web.config I tried adding App.config with the needed setting, but this was not successful.

Has anyone had same issue?

Thank you.