Some missing track presets issue

It’s quite a simple problem but at the moment I don’t know what the answer is to this phenomenon: I noticed that in Cubase the “mixing”, “standard” and “record” presets disappeared from the track preset section, only the “simple” is available. (Project window, bottom menu.) Only this preset is available in the track control settings too. I’m sure I haven’t removed any of these presets. Was this caused by an accidental change of some setting, or were these presets somehow simply deleted from my machine? Because these presets are obviously stored somewhere in one of the Cubase subdirectories. Anyone have any tips? It’s not difficult to reset these presets manually if you know which buttons were active for each preset but it would be nice to know what caused this strange phenomenon.