Datasheet, page 6:
Other handling precautions
▼That using the wrong pressure range or mounting method may result in accidents.
▼The only direct pressure medium you can use is dry air. The use of other media, in particular, corrosive gases (organic solvent based gases, sulfurous acid based gases, and hydrogen sulfide based gases, etc.) and media that contains moisture or foreign substances will cause malfunction and damage. Please do not use them.
EDIT: to make it clear, your device can't work in water and may very well be already dead