I have flats D'addario chromes on my elan4 and the strings feel really tight. I have been getting some buzzing/choking on the E string from 5 th fret upwards and from 7th onwards on A and G strings but not on the D string. i tried adjusting the truss rods to get some relief and now they are loose and strings are choking out. Any suggestions. I am wondering of there are some high frets as the bass was refretted when it was resprayed.

Just a couple possibilities Jazzy...

1.) Your bass is experiencing some seasonal changes in relative humidity, that has induced some backbow. Higher humidity can do that.

2.) The refret may have been done with fretwire with a slightly heavier tang. That would also induce backbow. We do it on purpose with guitars that have no adjustable truss-rods. It's called compression fretting.

3.) Maybe you do have a high fret or two, or just a "bucked" fret end. There is a tool called the fret rocker for locating them. Any guitar tech should have one.

Try this first. Put a capo on the first fret, and then hold the E string down at about the 19th fret. Wherever the neck meets the body. Check for relief at the center of that span... 5th - 9th frets. Is there any, or is the string touching all those frets? If there's clearance you'll see it, or hear it clink if you tap down on it.

Thanks  Ed. Will check that out.

Ed's notes could absolutely be right; might be a fret issue, or humidity.
One other thought - I could be wrong, but I actually was under the impression that the general rule-of-thumb is:

• If you're getting buzz on the lower frets, but not the upper frets, it's likely a string relief (truss rod) issue.  I.e. the neck is too straight, and needs some forward bow.
• If you're getting buzz on the upper frets, but not the lower frets, it's likely a string action (bridge height) issue.  I.e. you probably have at least some forward bow already (which is good), since the lower frets are playing OK, but you need some additional height at the "bridge" end to make sure the string vibrations clear the upper frets.

Have you already tried raising the bridge?

Of course, the reality is that it could be both, and/or addressing one thing can affect the other, etc.  But I just wanted to throw out the suggestion.

Either way, the "fully loosened" truss rod issue is still unfortunate, because even if raising the bridge fixes your issue for now, you're still right at the very end of the adjustment range on the truss rod.  It might never be a problem, but if it later turns out you do still need more relief, there's no more adjustment range.
I've had this issue on both of my Alembic basses, unfortunately.  Too much backbow seems to be a far more common issue on Alembics than too much forward bow, for whatever reason.
My understanding is that pretty much the only way to increase forward bow once the truss rods are fully loosened is to do a heat press.  Alembic did it for me on my first bass, for the 2nd, I did it myself.  It actually worked, at least in this case.  My truss rods are still fully loosened, but at least the relief is now fine.  I made some notes on how I did it in this thread:  https://club.alembicguitars.com/troubleshooting/truss-rods-stuck/msg300630/#msg300630

Hope you don't need to go there, but if you do, just know that there are still options.

Buzz on the upper frets can also indicate a relief issue: too much relief. If you try to get the action low on the lower frets with too much relief, as you play up the neck (deeper into the relief) the string can contact the upper frets.

I'd suggest tightening the truss rods to decrease the relief, then adjust action accordingly, see what happens.

Have you measured the relief? Put a capo on the first fret, press the string down at the fret where the neck meets the body, then measure the relief with a feeler gauge halfway in between (maybe around the 7th-8th fret).

My Alembic bass came back from a recent PLEK at Mike Lull Guitar works with the relief measuring about .007", that seems to work pretty well. But it's very much a function of your playing style, so adjust for playability first, then measure and remember that for future reference.