Where did I go wrong, or is it Meh's fault?

5

So some of you may recall I asked for Meh’s help in watering my plant I got for Valentine’s Day from the hubby. It is doing well (on the right). But that same week I decided to get a cilantro plant too. I have done cilantro plants before, at my last house, with relative success (most would last 2 or 3 months before they turned brown on me).
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As you can see, the cilantro plant is falling out - not turning brown but withering away.
The plants are in afternoon sun. I water both about 1-2 times a week, and the soil never feels dry, and also never too wet (both are in containers on a plate). The sun room they are in is about 60 F.
What did I do wrong? Or even though I asked Meh for help with the plant only, is the cilantro disaster Meh’s fault too?