NEXT button not active on Review Results

I have checked previous answer on similar theme but none of the solutions seems to solve the problem I encountered. This is as follows:

I inherited a complex set of 15 long modules that used an ad-hoc player. I changed it to the Modern player and all works but in the assessment area (which I 'sanitized' and attached here in a simple 4 Questions + Results set of slides. 

You will see that there are a gazillion styles both for Master Slide and Master Feeback, and this set use respectively only 2 + 2 (they are in the last stylesheet in both types and I cannot remove the prior one oddly - but this is another question). 

Q1 correct answer is A and Q2-4 is B. As the pass threshold is 70% if one gets 1 wrong and 3 right it gives a nice 75%. This is the scenario with problems (if one pass 100%, the Success Layer is evoked, and all works fine). But for this scenario (which leads to Unsuccessful and has a Review button with Only Wrong Answers set) thins are not ok.

Triggers are mapped against the standard modern player buttons, no odd triggers hidden in Masters, Menu restricted (but this is how it is supposed to be), in all Q's Base Layer settings are apparently ok (Next - Submit - Player Navigation, all ticked [only Prev is off]) with advance by user, Automatically Decide on revisit and the correct mapping to Results Slide.

...BUT...

...when one review, the Q1 is ok, only that there is no NEXT BUTTON. And I cannot understand why. I would also like to show NEXT in letter close to the > but at least the next function in review, otherwise the user would get stuck. 

I feel a bit dumb but have exhausted all the possibilities that came to mind and I never came across this problem, so I suspect it has something to do with converting from an old ad-hoc player to the new one. Yet, it is the only way I can complete this as there are other requirements to keep things looking as the originals. 

Any clue or hint? I would be really grateful for your help. I attached the file.

Thanks in advance.

Andy