What should I do

Looks more environmental... Little tacoing along edges -- heat 85-86+ F and/or low humidity less than 40%. Lower humidity will cause that sort of tacoing at lower temps, too. Grow lights trick the eye and the camera. I bet the slight difference in interveinal color with other parts of leaf are an illusion - shadows or angles of light causing a visual difference that you won't see in normal lighting. Check them out under normal lighting and i bet the color is consistent - gently flatten any rippled leaves. I've been tricked by this before, too. Take it into some normal lighting and re-assess. The ripples are a sign of being full of water -- in and of itself not necessary a bad thing. if you have good watering habits, then they are no issue. N-tox.. i don't see it. This would progress at the bottom and move up the plant. The leaves will get darker and even glossy as it progresses. these are mostly great looking leaves with a little tacoing going on that is usually climate related. If you don't see this progression, it is not an N-tox. I'd wait until you observe what i'm describing before tying to reduce N in substrate any futher... Flushing is a useful tool but it is a drastic one. It slows your plant down and takes away other thinsg that were in balance but maybe not after. Anyway, even if it was a n-tox, it's clearly slow-moving.. a slight change to your fertiization formula should be all that is required and no need to flush a substrate and get all the negative effects that come with it. Usually 1 part has the highest proportion of N, try to adjust that down without impacting other nutrients as much as possible. drop weighted average of N 10% and see how that goes over a couple weeks -- again only if you see the progression described above.