My guess would be Magnesium deficiency or possibly biuret toxicity if you are using a urea based fertilizer.

I use Jobes Organic Citrus fertilizer and fish fertilizer (though havent used any fish fertilizer on it yet) so not sure about biuret. I can try some Epsom salt but believe I used some of that about 1-2 months ago.

On a side point do you know the pH of your soil? If the pH is off it can effect fertilizer uptake, citrus is generally happiest with a pH between 6.0 - 7.0 when grown in ground, I am not sure about container growing.

If in fact your plant is suffering from a nutritional deficiency, it may be due to the fertilizers you are using.

Organic fertilizers and fish fertilizer are poor choices for fertilizing potted plants because they require microbes to break down the fertilizer into molecules that the plant can take up. Such microbes are not present in sufficient numbers in the soil mix of potted plants. Organic fertilizers are fine to use on in ground plants because the microbes are present in the soil in sufficient numbers.

Use Foliage-Pro 9-3-6 or Jack's professional 25-5-15.

I chose Jobes because it has combination of soil fungi and bacteria designed to help augment soil microbes. Haven’t had any issues with any other of my potted citrus using same regimen (key lime, persian lime, eureka lemon, limequat).

As for pH, I’ll have to check again to see what it is currently. I checked it several months ago and it was around 6.

Haven’t had any issues with any other of my potted citrus using same regimen

Just because you have not had issues with other plants does not mean that your fertilization regimen is appropriate.

You’re welcome to disagree. But if my “inappropriate“ regimen is getting the results I’m getting with hundreds of blooms, developing fruits, and tons of new shoots, then I find it hard to justify changing it.

Even the Satsuma is loaded with blooms and fruit. Only concern and difference compared to other citrus was the leaf color.