I know you're an experienced grower but I'd still venture overwatering add/or nute wash because of it.
Thanks Paul, not a complete noob, but not as experienced as others. But with or without experience, this is driving me crazy, because still have same problem, with these, and with a Lanceolatum too.
I'd say no overwatering, but even if it was at that time, I suppose should "heal" till now, right? Because in the last time I am "fingering" them before watering. If I see a need of water, I am watering with limited quantity, and repeat, little by little, till I see the water is coming out off the bottom. The pots have no plate under them so no water will remain there - which could confirm your nute wash idea, but as I said, I am watwering them step by step and not let much water to run out. I also did used a foliar nute, which will not wash when watering.
I am working now, but I hope will find some time later to post new pictures.
BTW, I did checked the bottom of pots, and is completely dry.
Maybe will repot them again - the Rhombos. Lanceolatum was recently repoted.
The good news is, I see some small flower buds of one of Rhombo.