One for the rack experts:

Beggining a few days ago, the low liquid level alarm of the receiver started to flash. I guess it is some kind of float device. It is triggered whenever the level of liquid refrigerant in the reciever drops almost to the same height of the receiver outlet pipe. I added a few kg of refrigerant, and the alarm reset, just to repeat itself the following day.
This situation did not happen before.
The only work I have been performing lately was the opening, blowing and oiling of the evaporator pressure regulating valves, and the TXVs of several circuits. But I am quite sure I did not leave ane leaks.
Some fellow told me that now that the TXVs and SORITs are working, and the TXVs are really feeding th evaporators, the liquid refrigerant that used to back off in the receiver is now flowing more freely, which translates into a lower than before liquid level in the receiver. Could this be true?