Sling hasn't eaten in 2 weeks and seems stressed

Hi, I'm very concerned about my new ybyrapora sooretama sling. They arrived 6/30 and I have attempted to feed them every few days since then to no avail.

They seemed interested in food once on 7/7; they grabbed the dubia and sat on top of it for a couple of days. I thought they might be eating but when I removed it it was intact and uneaten.

Every time I try to place food near them I just end up scaring them, and it goes uneaten, but leaving it farther away and I don't think it's ever found.

They haven't built any webs and seem to be very sedentary and often in the scrunched up position that I think is stressed?

At what point do I need to really start worrying? Do they need a smaller enclosure or some other change? The current one is 3x3x6". The sling is probably .5". Their name is Fig and I don't want them to die :(