FX FX Wildcat MK3 BT leaking

Hello,

My FX Wildcat MK3 BT's first reg manometer shows leaking. I filled it up to 250 bar, and the pressure went down to 230 Bar within 2 days but was holding steady at 230 bar for a week. I thought it was because of the change in temperature. I left it alone for 2 weeks, and the pressure went down to 190 bar. I tried to find the leak by spraying soap and water, but I couldn't.

FYI, I had this problem when I was using the original FX regs, and I changed both regs to Huma's because I wanted to shoot high power anyway. But the problem with the leak continues, while the first reg is stable.

Any lead to solve this problem?

Thanks.