Just installed 4 barker deli cases and having trouble making temp and running out of ideas.

Case model PF-8 and PF-6
The txv is frosting after the valve and the frost doesn't make it through the first pass. So what I did at first was open the valve up a bit to get more flow with no result.

The valve in the 8ft case is a SBQE with AA cartridge and the 6ft case has a SQ with a 2 cartridge. The valves came with 404 a power element and the rack is running 507.

I verified all cartriges were correct from the factory.

So I had no luck opening the valve so I installed 507 power elements on with no change.

I checked the spec sheet and case is supposed to have 200fpm DA which is does.

Also Added a sightglass and access port in the liquid line.

Full column at the txv and 180psi liquid pressure.

At case liquid 180psi
78* F liquid line temp
SC around 3*F
Suction 55psi
55*F suction temp
SH 37*F

At rack

Liquid 180psi
Suction 54psi

I currently have one txv all the way open with little to no change.

Any ideas? Thanks in advance