Does that 90g/day take into account that some proteins are incomplete and shouldn’t be counted gram for gram?
(bonus “tip”: when counting only adding up the calories from the main macros of a food is a convenient way to create a surplus. I.e. If you need 2500 calories to maintain, and you have a 40/30/30-macro split you’d sit down and plot out whole food sources (yams, rice, oatmeal,…) that add up to 200g of carbs, and then repeat the exercise with protein sources getting 188g of protein and finally again for fats. In the end you’ll have a surplus)
I feel the easiest way to check if this is the problem would be to “simply” increase your protein-intake (no other changes! You do not get to reduce carbs or fats) by adding a 6oz serving of meat, fish, or a suitably sized serving of cheese, cottage cheese, quark, or a couple of servings of yoghurt, kefir, and milk. Live with the change for 2-3 weeks at least.
I say simply because if I don’t misremember your kidneys are unhappy? I know one person that had to reduce their protein intake as a consequence of their kidney problems and he takes sodium bicarbonate to buffer the acidic load of their protein intake but you take in so much (too much) vegetables and so I don’t think this should be necessary. Conveniently(?), that’s CT. He takes 12-25g/day but he eclipses you physically and I don’t know how he arrived at those numbers and if it scales linearly.
I say conveniently because he is usually very responsive on his subforum if you’d like to inquire more.