Water Chiller lost performance. Help getting it back to performing at top temps -21c

[chispy]

Hello XS , i need some help with my Hydro-Farm ActiveAqua 1HP water chiller - https://hydrofarm.com/p/AACH100 . I bough this unit cheap and barely used here where i live and it was a very good deal cheap for a 1HP water chiller. I did mod the controller to let the compressor run and never stops , always On so that i can bypass the max 32f or -0c restriction of the controller. So far so good in the first few months it was running perfect at maximum -21c using Car antifreeze Glycol /H20 50/50 mix , everything is well insulated and i use a very strong pump PANWORLD 100PX PUMP 790 GPH. This is not my first water chiller and i was let down by the loss of performance after 6-8 months of use , it is also the first time i have encounter this problem :/ . The water chiller right now won't go down all the way to -21c like a few months ago , it has lost performance and now it is going down to only -5c , wish is nothing for today's hardware as i need it at least -20c to hold the temps when loading Intel's 9900k / AMD 2700x on benchies.

The problem started around a month ago after running the water chiller for 12 hours non stop using a Ryzen 2700x at 4.8Ghz and a RX570 GPU moded and overvolted ( heat monster under load lol ) on 2 separate loops off my moded igloo external reservoir using only one water chiller for both heat monsters. After that day I noticed my cpu crashing under load and it was hitting very high positive temperatures the next subsero session i did. I kept waiting for the water chiller to reach -21c that day ( 6 hours ) and never happened , it was hitting maximum -5c . Since then i have troubleshoot the water chiller with no good outcome and i have not been able to make it run at -21c again. I flushed the reservoir on the water chiller , cleaned everything and re-did all the insulation , cleaned the water blocks and the water pump , change and use new tubing on it , use new mix of glycol and H2O 50/50 same formula as before , cleaned the whole chiller and nothing that i have done has work in order to make it run as colder as before at -21c iddle. The only thing i can think of is a R401a gas leak or maybe i damaged the compressor i really don't know but if anyone can give me any advice or help to get my water chiller running back to very low temps -21c again it will be really appreciate it.