I can confirm that the Job history page does not work as intended for most of the leagues.
I tried: Slovakia, Denmark, Romania, The Netherlands, Germany, Czechia, Bulgaria, Poland, Switzerland (and probably some more that I forgot). For each of these instances I picked the earliest start date, and the job history page remained blank, even after playing the first match of the season.
For some leagues I can get it to load by fiddling with the start date. For example by picking another country’s start date.