2002 V70 Failed emission - no code yet, but small leak found

[vtl]

So, first time in life, failed inspection VIDA showed "evap monitor not ready". I did a "quick fuel tank test", and it showed a small leak:

Engine had difficulties with idling through the test when the pressure in a tank was dropped the most.

No I'm trying to figure out what needs to be replaced...

Evap purge valve (near radiator) had rubber hoses in a bad shape, I replaced them with silicone. Same for MAP.

Charcoal canister had the usual suspect hose apparently replaced, since it looked newer than everything around. And I can't see any cracks or signs of wear on it.

So how I understand the situation:
- the purge valve works, because pressure in a fuel tank drops when it works
- J hose was previously replaced and does not have cracks in usual place
- canister is not generally known for cracks (?)
- the pressure drops slowly with the shut-off valve off (green line is high) and drops much quicker with the valve on

So, looks like the purge valve is the culprit?

What the far upper tick hose is for on a canister? I don't see it in VIDA diagram, it has only a J hose to shut-off valve and another thin hose to a purge valve.

[vtl]

Got it, the hose goes into tank.

[vtl]

Found one leak...

Ran the test with 10-years old fuel tank cap from 2005 XC70, and it showed "20" instead of "100" (whatever this number means). Accordingly, the tank was dropping vacuum much slower. Two new caps put on order.