Weapon whitelisting

Pressure Washer V2 gives the player the weapon WEAPON_PRESSURE1. Inventories and anticheats that manage weapons will strip it the moment it is handed over, which looks exactly like the script being broken.

ox_inventory

Add this to your server.cfg:

setr inventory:ignoreweapons ["WEAPON_PRESSURE1"]

If that does not work, open your ox_inventory's init.lua and add:

ignoreweapons [`WEAPON_PRESSURE1`] = true

Note the backticks around the weapon name in init.lua — not quotes. Backticks make it a compile-time hash, which is what ox_inventory expects there. Using quotes will not match.

Running the Fire Hose as well

Whitelist both weapons:

setr inventory:ignoreweapons ["WEAPON_PRESSURE1", "WEAPON_FIREHOSE"]

ignoreweapons [`WEAPON_PRESSURE1`] = true
ignoreweapons [`WEAPON_FIREHOSE`] = true

Other inventories

The principle is the same whatever you run — the inventory has to be told to leave this weapon alone. Look for an ignore list, a whitelist, or a "non-managed weapons" setting.

Anticheat

Add WEAPON_PRESSURE1 to your anticheat's allowed-weapons list. If the gun works with the anticheat off and not with it on, that is your answer.