Walk in freezer evaporator freezing up?

[Ben23]

Hello everyone. I have been trying to suss out this zanotti ealk in freezer that the evap coil keeps freezing up on. Its not low on refrigerant but the evap coil on fan side is like a block of Ice. The suction line is froze as well as the top of the compressor and the capillary tube was frozen too it doesnt have a txv. I thought it was a defrost issue changed the defrost sensor and the controller for the unit with no joy. It quickly comes dowm from 10 to minus 2 then sticks amd starts to freeze up. I have no clue I normally work on systems with a txv.
The photos of the capillary its using after defrosting it all.