Lost in transition: Seeking guidance on my career path

I am a 2.5 years of experience guy and I have been at my current company for almost 2 years. The learning was good in starting but from the past 6 months it has been a very stable environment with limited learning opportunities.

So I decided to switch jobs, but i came to know that despite working on many technologies and handling many deployments on my own, i did a very little work on the scalability of our systems like synchronisation.

I am feeling very dumb downed right now, i have messed up a few HM rounds due to this. Once an HM asked me to rate myself on java i told 7, I told him that i have studied and practiced advanced concepts myself but i don’t have hands on experience in advanced concepts. He didn’t asked me any further questions related to java and i got rejection from HR with the comments from HM that “weak in java”.

Also i am earning around 22 fixed but i feel i need to switch job else i will be left behind.