[LEAKYSEALS951]

Reason I ask- if it's a new chain, it might be a link or two too long.
edit- nevermind=you beat me to it

There is something called a "b" screw- it's in your pic, which can move the derailleur back, but if the chain is too long to begin with, might be better to remove a 2 links to get the tension.

What you want to see is
How stretched is the derailleur in the "8" position?
How stretched is the derailleur in the "1" position?

Post some pics if you get a chance.

plenty of YT videos on adjusting the derailleur b screw, but want to see the chain at the extremes.
Worst case scenario with B adjuster- turn it to pull the derailleur back, remember the # of turns you turned it, and turn it back if it doesn't work. Adjusting the b screw can affect shifting responsiveness because it essentially pulls the derailleur away from the cogs sometimes.

Seeing how stretched the derailleur is in the one and eight positions, and how loose the chain is in those positions (floppy, loose etc..) is a good place to start.

Also- longshot, make sure you don't have a bent tooth on the front chainring. A single bent tooth can throw the chain if tension is low.