Okay so like some of the other guys on the site, I am new in the refrigeration side of things, Have been doing air conditioning for quite some time. I am stuck in a jam with a freezer that I am working on. Let me explain.
Okay the box is brand new, 10'x18'x6' 4" thick walls, has a walk in door and 6 reach in glass doors on the front.
My condensing unit is a 5 ton, R404A, Has a receiver, sight glass, and a filter/drier installed inside it. Unit is located outside. Outside ambient temp is typically 85-95 *F in the summer.
My indoor coil is a 5 fan evaporator with a 1/2 - 2 ton TXV installed. also R 404A TXV is all the way open.
My indoor coil get frost on it, like snow, and my outside suction line gets heavy icing on it, as well as the compressor. I have bubbles in the sight glass.

I know my problem lies within the undersized TXV and the undercharge, but I would just like to know what is going on with the system, the science behind WHY the compressor is freezing up, ect.

Thank you gentlemen in advance!
Any suggestions are appreciated.