It's always better to rip a Band-Aid off vs. doing it slowly, so...

Tear it all out. Right hand side bottom, your blocks are sitting directly over the ones below, no stagger = failure point

Left hand side, instead of just terminating into thin air the block should return back into the slope, for both aesthetics and stability.

If the block was set on sand, that's incorrect and will cause failure down the road.

What is going on with that third step down? It looks out of level with everything else and the cap is super wonky.

The pavers should all be flush with the wall caps that are forming your step treads, If you've already had so much movement that they've settled what looks like nearly an inch, you're in some serious trouble.

There's no patch that will fix this, these steps have terminal problems that will only get worse. All planting around them will do is make it harder for the EMTs to collect the first victim.

oh and mortar is wrong wrong wrong for a segmental retaining wall. You use a poly adhesive. Whatever stone yard the blocks were purchased from should have supplied that.