I’ve got a very similar experience to you. Bought a barista express at half the price about 4 to 5 years ago when it was on clearance (display model) at half the price. Impulse buy but honestly one of the best purchases I’ve ever made. Years later I still can’t get a consistent froth on my milk.
I’ve noticed that the steam wand produces a different pressure of steam every time. Sometimes it’s like a jet and sometimes it’s just a whistle. Spoke to a technician that came to repair my pressure gauge and he told me it probably wasn’t cleaned out properly but I clean it and flush it every time. Even drown the thing in milk detergent after every use.
Still, have loads of fun and coffee is great by my standards
I’m just waiting for the fast food to join at this point because I’m Lovin it