Issues with flow and heat (RosMax3)

[Or1g1nal1ty]

Okay so I've been making a few prints and adjustments based on some other trouble shooting steps I've seen. My first benchy was subpar to say the least. Some changes to the eeprom I saw here made the second much better!

But I had some issues with a series of very simple shapes, including a 2mm thick hollow cube attached here. The sides are near perfect but the top was stringly and didn';t even have filament in most of it and fell into itself. Any recommendations what my next fix should be?

Note: this is my third 3D printer and first one that's not a tiny prebuilt thing.