gently tip it out of the pot.. and find out just how bad the roots are circling.. and look closely at the media and see if you can tell its worn out ...

it looks on the verge of being a bit big in the smallish pot ... and i suspect worn media.. ,leading to proper watering issues

and perhaps a nutrient issue of you dont feed it once or twice a year ...

its also leaning ... so there is a light issue.. at least turn it once a month ... but as you note.. the node growth seems to indicate its not getting good light ... i presume you out it on the table for the pic ...

in other words... lets look at all the cultural variables.. before we go toward bugs.. and slathering all kinds of goos on it in hopes that maybe a bug is your issue ...

ken

and then slip it back in the pot.. after taking a few pix .. and lets see where we go with this

Hi Ken! Yes it has lots of roots circling, see photo. Actually when I bought it a few weeks ago it had lots circling outside of the pot, but those were pretty rotten so I cut those off.

It's indoors so not greeting amazing light but it is directly in a southern window, and all the surrounding plants, many of them ficus, have quite short internodes.

I actually don't bother to rotate most of my plants, it strikes me as almost paining the plant, after it reaches one way to make it reach the other way.

The only reason I ask about spider mites is that I suspect spider mite damage on another plant and it looks similar, see the last photo

For a few dollars, you can purchase a 5-10X magnifying glass with a built-in light that will take almost all guesswork out of spotting/ identifying very small freeloaders, like mites. EXAMPLE

F altissima doesn't have a particularly compact growth habit, but your specimen is a bit leggy, to my eye. The plant normally begins life as an epiphyte, fighting it's way through the understory until it finds a full tropical sun position in/above the canopy. So, it will certainly tolerate, even appreciate full sun; and, while it can't be said it must have more light to remain viable, it does need more light if you are looking for a fuller and more compact plant. If that's your goal, you might consider chopping the plant back and starting to pinch it (from now through Sep) back to 2 leaves per branch once the branch has grown 3 leaves. Also, as soon as you see a new branch growing in a leaf axil, remove that leaf.

Example:

On established trees, you would want to remove the 2 mature leaves with new branches growing in their axils as soon as they reach this stage. I hadn't removed them because this is a newly rooted cutting and it needs the extra energy those leaves provide (for the time being).

Your plant would benefit from repotting, but it's not yet at the stage where more than half of it's potential is being sacrificed to root congestion, but it will be by 2022's most appropriate repotting time almost exactly a year from now. You could cut through the large roots on the perimeter of the root/soil mass somewhere close to the top of the soil/root mass and pull the encircling roots off the bottom and trim, then pot up, and plan a full repot for Jun 2022.

Have you been fertilizing the plant regularly? It looks like it could have mites after it, or it needs to be fertilized ...... perhaps both.

Al