3rd week of flower, first signs of issues, please help ;(

What's going on everyone, so I am having some issues with 2x of my girls that are in wk 3 of flowering. I'm guessing CalMag deficiency to some degree? Would just like 2nd opinions. I haven't run into this issue before in the handful of grows I've done. They haven't exhibited ANY issues this entire grow up until now so I am a bit perplexed.

1) Pictures are attached!!!
2) Growing indoor or outdoors: INDOOR
3) Watering schedule: Every 2-4 days
4) Growing Medium: Soil in 3Gal smart pots
5) What stage of growth: 3rd wk of flower
6) Temperatures: 72 all 12hrs of light
7) Light: LED 21" away from canopy

I am hoping y'all can help me out with the issue I'm experiencing.

Nothing in the grow has changed other than their last feeding...Instead of feeding 1x plant at a time with it's own serving, I made 2x servings in 1x bucket for both plants. I'm not sure if that has something to do with it, but these symptoms happened SUPER fast within 2 days and not entirely sure what is happening. Some of the leaves have tips cut off just from being dead dead and trying to cut it off.

Any and all help is appreciated and I'll answer any questions to help figure it out.

Thanks!

.

Looks like the opposite symptoms of mg def - the veins are fading to yellow while the margin is staying green.

click on the charts to enlarge.

.

.

.

That new growth looks way too green for me , I would say over fed

I wouldn't ph ya water either as ya soil will have buffers to adjust the soil anyhow

over fed.