+1 The chainring is off center, and acting like a cam. Possibly this is in the crank and spindle interface or possibly the chainring isn't mounted properly on the arms.
If, as it appears, the chainring is supported on shoulders on the crank arm spider, there probably isn't any float to recenter the ring on the arms, but if it's supported by the chainring bolts alone you might be able to float it closer to center by loosening the bolts, then tightening them firm and tapping the ring in the appropriate direction until it runs true. You can do this with the chain on using the tension changes as a guide. When you've achieved the best position tighten the bolts .
If there isn't enough float to get the ring centered, or if it's supported on shoulders, then either the chainring, crank or spindle is defective and needs replacing.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.