Pcv breather "burping" noise, after replacement

[Ragman]

hello all,
i ended up replacing my pcv breather trap, after noticing some oil leakage, and due to it being the original, from what it looked like inside. its a 2012 XC70 3.0 turbo, with about 268,000 on the clock. when i got it at 186,000 i did the due diligence and replaced the plugs coil packs, filters ,etc, and the car had no leaks and runs strong, but with some oil consumption, that i think is higher than normal. ive been running a double dose of the Yamaha Ring-free in the fuel, and it has helped a lot. previous owner was not very careful with the maintenance of oil changes. im guessing now that the burping noise has been there n but hidden due to the fact that the screws holding the breather down were loose in places. Any suggestions on what I might be missing, are helpful for sure. Also notice vacuum at the oil fill neck, when I open it , while running, and then replace the cap

Thanks, Pete