Fwiw: I once had a bum FSA Vero crankset that somehow got a single arm of the crank spider bent. I bent the ring back as flat as I could. The bent arm & counter-bent ring never manifested into a problem unless I was laying down watts & usually only then when powering down a steep grade at 30+ in the small end of the cassette. Fun times in WTF(!?) Land...
A new crankset solved the issue.
I now run an oval road ring with perfect chainline. The tension is all over the place because, oval. Not a single dropped chain. Ever.
Did you recently switch to a new chainring & place it in the inboard or outboard position differently than the previous one that was removed? That would move it from "perfect" to off by at least more than 5mm & less than 10mm. That's a wicked mis alignment.
I question that chain tension is the root cause unless the chain/cog is so worn that it can climb over the cog teeth. What does a chain wear tool suggest?
Even then, it would need a reason to want to misalign & hop off. It could be a combination of both. Hence, the above.
EDIT: Now that I see a picture was posted while I was typing my reply...Chain tension is totally what your problem is. Tighten that ish up, man! Good gawd.
