I've got a question for the commercial refrigeration experts about a walk in freezer.

I've got a question for the commercial refrigeration experts about a walk in freezer. I primarily work on HVAC but now I'm in a job that requires HVAC and some refrigeration. I thought I could dust off that knowledge and figure this issue out, but apparently not. Anyway I'm working on a TEHA015L6-HT3D-F, with a TPLP207LES2DR6. The system has been maintaining -5 for years, and then recently it started gradually gaining temperature up to 17 degrees. The superheat was 45 degrees, head pressure was high and suction low. I initially started to attempt to adjust the TXV and found the adjusting screw all the way out and not able to be adjusted. I rebuilt the TXV, new cartridge, and new screw adjustment. I made sure to purge the screen even though it could not be removed. After that repair same symptoms, evaporator still starved and appeared to have a liquid line restriction. From the different temperature readings( on either side of the valve)I determined the head master was the restriction. Once that was replaced (including the filter drier,) I still have the same symptoms. This is a R404a charged system and has had fresh R404a added after the TXV rebuild. Box temperature doesn't go below 20 degrees. I have -12 degrees sat, with 17 degrees pipe at the outlet of the evaporator with 29 SH. The condenser is reading 109 degrees sat, with 105 degrees pipe at the outlet of the receiver, with 4 degrees SC, and the ambient has been in the 80s. The evap TD is 20 degrees rtn and 19 degrees sply. Suction temperature at the compressor is 51 and disch 195. Compressor is reading 5.4 A with a RLA of 6.3. I'm thinking I still have a liquid line restriction, but not sure about that. Its probably something easy staring at me and I'm overthinking it. Any thoughts on resolving this are greatly appreciated.