2 girls 1 pot *****YELLOWING Issues ****

I have two clones in a pot and Im noticing it’s getting super yellow and today I saw brownish spot any idea what it could be? I added cal mag To help but don’t see any changes

People far more experienced than myself but I did 2 outside in 1 20g pot and was told to never drop 2 in 1

You have got to let them babies dry out! Yeah, you can thoroughly soak your pots when the plants are that size, but then you have got to let them pretty much dry out, the pots should feel super light before you water them again. And your plants are telling me that you aren't doing that. The leaf tips are abruptly sagging downward because they are constantly being over saturated with water, then many of the leaf tips are rotting out because they cannot transpire all the water you are giving them fast enough. So again, please water them less often and also try to raise the temperature and lessen the humidity in your grow area when the lights are on to help them transpire all the extra water they have been getting!

2 Plants, 1 Pot, No bueno
You need to give more details, and show a full plant pic if you want serious considerations.
Your stems are super purple...unless it's genetic, it's a huge indicator you're short on Mg, but since we don't know pH, growing medium, feeding practices, nutrients, temps, humidity etc, you might as well, put on your blindfold, spin the wheel and throw your dart.

Thanks for your help everyone and I apologize for not putting enough information to give you some more background on it
pH is 7.4
growing medium is fox farms
feeding practices I have not added much nutes to it so I water her every 2 days (1 liter )
It is In week 4
The tempeture range from 75-78 degrees. Humidity is around 40-60 %
i am also attaching more pictures of the plant for further review thanks again for taking your time to help me out

I would encourage you to do one thing and one thing only at this point. Dial in your pH...7.4 is too high...you need to be @ 6.5. Once you get your pH dialed in, then give the plant some time to show deficiencies or not, otherwise you'll end up chasing your tail.

I am no expert but like everyone here says 1 plant to 1 pot. Also it looks like it maybe may be a magnesium deficiency because of the yellowing of the leaves but the veins are dark green. Like others have said pH is a little too high. Look at the chart for pH ranges. The left side is for hydroponic (coco, etc) and the right side is for soils.

1 plant to 1 pot
looks like root zone competition to me
my 2 cents is to transplant or kill the weaker plant

I think that the best thing to do is to plant one plant to one pot and then wait to see if things improve. If not, then come back here.