Disease identification

[TonMz]

Hi everyone. New here.

Can anyone help identify these issues? If solutions are also suggested, I'll appreciate.

Are all of my palms rotting? I gave them a replant with palm soil from Bakker, extra grit, gravel, sand and coco coir which I mixed the palm soil with to create more for all my palm plants. Maybe the sand was too heavy or too moisture retaining? I barely water them, only watered them after transplant... And left them alone... that was a month ago. The coconut I saw going brown and read it needs weekly watering so watered it but it seems it is still browning.. The eternity palm, (if I've got the right name), was yellowing and since i hadn't given it water for a month, I watered it.... The leaves went light green... In 24 hours... Remarkably.. But the next day were yellow again...