Before you go ahead and replace components… could you make sure that’s really what the problem is?
Just remove the the silicone hose from the X connector and then block that port with a piece of silicone hose diverting to the tank, or remove the one which joins to the steam wand dead end and loop around.
Make sure the tube is dry - the one which comes out of the safety valve - and then see if it blows steam out.
If it does…
Replace with a like for like part. Bella barista should be able to supply you with the right one. Ps: I think that 3 bar for the Elizabeth is too low.
The one on the left is the anti vac valve. That one is the correct one I think.
Good luck.
Looks like Elizabeth’s safety valve is rated at 5.5 bar.