Pre-test issue (Lessons must be completed in order)

Hi, looking for some help. 

I've added two button stacks within a section before the pre-test. People can choose to take the pre-test (button stack takes them to the next section which is the pre-test) or choose to take the full module (button stack takes them to the section after the pre-test). 

When someone selects the pre-test option, I've tested this and all is working fine (both when someone fails it or passes). If they fail, they are forced to do the full module and then take the end-test. If they pass, they go to the end and exit. 

However, the issue I have is that when someone chooses to bypass the pre-test, and select the button stack that goes past this, should they then pass the end-test, the course says "Lessons must be completed in order" and they cannot get to the end. I assume this is because they've missed the previously pre-test completely.

Is there a fix for this? 

I've attached two screenshots.