There are two implementation of conditions in the platform:
V2 (which you intended to use) - accessing form field values through getValue(), eg. getValue("GesCheckbox1") === "true"
V1 - accessing form field values by their IDs, eg. GesCheckbox1 === "true"
By default, the conditions are evaluated using V2, but in case an error occurs, there will ba a fallback to V1 - there is no getValue() function in V1. This explains the log entry.
Probably the ID you provided (GesComplexComponent74_GesRepeatableSection1_row0_GesComplexComponent74_GesCombobox1) is incorrect - platform uses a period, not an underscore, as a separator. So, the correct ID you want to use is likely GesComplexComponent74.GesRepeatableSection1.row0.GesComplexComponent74.GesCombobox1.
However, returned value may be null or undefined so you should check it before calling .length.