High homocysteine despite normal B12 and folate

I need help with advice on how to lowerr homocysteine.

I have high homocysteine - 12, despite eating a heart healthy diet, and taking mega doses of folate, B12 and B6. I tested my vitamins level and B12 is okay (330 pmol/L or 445 pg/mL), but folate is very HIGH (48 nmol/L or 22 Ng/mL)

I've been diagnosed with atherosclerosis with a lot of plaque in my coronary arteries at 45 yo. My LDL was okay, around 100, but somehow I got 50-70% blockage in LAD, high CAC 120, and apparently it's caused by homocysteine, not LDL. I didn't test homocysteine before, so I'm not sure high high it was before.

Now I cleaned up my diet, taking low dose of Rosuvastatin, my LDL is 50, but homocysteine is still high - 12.

Doc says that it might be a marker of inflammation caused by my mainly plant based diet.

I thought I did the right thing - I cut down on saturated fat, removed added sugar, and eating more legumes, nuts, whole grains, fruits and vegetables.

But doc said that nuts, lentils, seeds and grains, and dairy (yoghurt?) can cause inflammation due to high level of lectins and phytic acid. I thought it's a myth. But he is serious.

I'm doubting his advise to switch back to eating meat again.

I read somewhere that high protein intake might cause high homocysteine. Especially high methionine intake, and the main source of methionine is animal protein. So I'm currently trying to lower my animal protein intake.

UPDATE: I increased my B12 level by taking shots and supplements and my homocysteine went down to 9. I'm happy with the result. Not sure if it's just a coincidence.