Is my current job limiting my potential as a Network Engineer?

To give a bit of back story, I'm 28 and I have been with my employer for 4 years after starting on their graduate scheme. With nearly 3000 employees they have different teams for network design, support, security etc.

My role was in Design, supporting senior engineers and working on my own small projects with their support.

Unfortunately I was placed within another network team for a good two years, where I had no work on an IP network. While I gained a lot of experience with 3rd party telecoms providers, and troubleshooting the physical components, it was not what I applied for.

For the past 2 years I have been solely on Design, it started off basic, but for the past 9 months I have worked on my first big project which revolved around Nexus switches which I learned by myself as they were new to the company.

And this is where my problem lies, a good 80% of the work over the past 2 years has been Layer 2 related, and my routing knowledge has got a lot weaker since I passed my CCNA two years ago.

My projects are due to change shortly, and I have asked for more routing experience. However, I feel like this is not enough. I look at other jobs to get an idea of the skills they require, and I see firewalls, load balancers and basic programming knowledge, none of which my current role requires.

But what I really want to know the answer to is, should I be worried with the lack of diversity? And should I look for a change of role?

Personally this is a big issue for me. I moved away from home for this job and to be honest I'm not really happy. I feel like I live to work as I have built this job up to be such a great opportunity that I should hold on to it for as long as I can.

I'm currently earning £40k as well, which to me is a big deal. If I go anywhere else I do not think I will earn as much due to the lack of experience they have given me.

I'm currently working on my CCNP, so I'm hoping this opens new doors to me whether that is where I am or somewhere new.

Some insight from anyone would be greatly appreciated, as I feel like I'm up against a mental battle of do I try and make a career and life for myself where I am, or do I start afresh elsewhere?

Thank you for your help.