Start by centering the chain ring as per Sheldon Brown's method and see how that improves the overall chain tension... if the problem cannot be resolved in this manner I'd look at replacing the chain ring to see if a different one resolves the issue.

I have come across a few bikes where no amount of adjusting could correct the variances caused by an out of round ring... the tolerances on some parts are not all they could be and if they are designed to be used with a derailer equipped bike would not be as noticeable.

Better quality ss and fg parts have closer tolerances and I have always been really pleased with Sugino chain rings as their QC is very high.

I wish everyone could provide videos like this.