Finding the balance in between productive enough and playing at work #techworkerproblems

Have a question about my career:

So far my career out of uni has been like this:

8 months in first place working as C# .NET dev, creating native desktop apps for windows. job was shitty, was not getting any best practices skills so I left.

12 months in 2nd place working as android dev in a startup. was working all alone and had to rebuilt my app up to 5-6 times to learn best practices. startup didnt care about android app at all so I left and now doing just some small freelance work for them.

3 months in new startup as android dev.Today I was told that its decided to focus on iOS and do all marketing (also uplift of new design) only on iOS. basically for next 3-4 months they don't plan to do much on android side. they saw that I showed some interest in backend and now they are asking me to talk with two other senior guys about starting with some small tasks for me on backend.

Our backend is mainly using python. Also backend guys will be pretty busy for next few months because they will have to deliver many new features in next few upcoming months. I've talked with one of them and he said that this is a bad idea to force frontend to start working on backend. However I feel that he's sort of gateekeping and probably just doesn't want to help me with getting up to speed.

In my defense, my knowledge doesn't end with C# .NET desktop apps and native mobile apps for android.

I have hobbie projects (gameservers) where I worked on websites (php,html,css,javascript,mysql) and also was taking care of a java based gameserver which is hosted in a linux vps.

Also I've had a small hosting "company" where with available tools I've managed to automate VPS(virtual private server) ordering, web hosting ordering and domain ordering. Basically I owned a dedicated server and did everything using whmcs, cpanel and proxmox virtualization.

I trust myself in learning this backend stuff and doing whats required, however I learned everything by myself and I won't follow all of these best practices.

Should I accept more responsibility on backend or should I continue focusing on android?