FX Fx king 600 reg issue

Hello everyone. I have a FX KING 600 mm with a reg issue, i had it set at 148 bar , but if don’t shoot it for couples weeks the reg pressure goes up, 🤯 to 190 or more , that’s weird i never had any issues like that before , so I’m wondering if any body had/has an issue like this.
I stored my rifle in case standing up just like a rifle rack, I’m totally clueless, I hope someone can help to figure this out. thank you very much.