Hips, Taz 5 or My Design?

I was having success with smaller prints on my new Taz 5. So, I tried to go for something bigger. I’ve printed this paper tray twice. Both times I’ve had bad curling in the corners. I’ve watched the first few layers go down clean, but when I come back later it has curled up by the end.

This my first larger design. I suspect it could be the way I designed it. After some googling, I tried a 2nd time with a brim. Same issue. I also tried closing all vents in the room and redirecting the air from the lulzbot power supply.

Any tips to avoid this curling would be appreciated.

Design:
3 mm walls
150mm x 100mm

Filament
Lulzbot 3mm Red HIPS

Taz5:
240C/110C
x bars even, all 4 corners checked with paper
Curling happened on all 4 corners

Cura:
Beginner
Standard
Hips settings


According to your picture, I would say your distance between nozzle and print bed (Z-Offset) is too high. There are gaps in your first layer!
Measure the height of a single outline of your print with a caliper, it should be exactly your 1st layer height. If it isn’t, adjust your z-offset.

Edit: If your nozzle distance is perfect, your e-steps value might be too low (under extrusion). But check the distance first…