Glad to hear that you got it working.
By default, the Gem collection mechanic comes into play only in the form of Exit Point becoming activated when all gems are collected. Otherwise, it shouldn’t have any direct impact on loading the next level.
So the first place I’d suggest checking if there is a mismatch in the loaded level would be the “LoadLevel” event. Try putting a breakpoint along its nodes and that will give you information as to whether the level index has been updated for the next map.