Friction with new team, PRs being ignored. Thoughts?

I've just joined a new company as their only dedicated frontend engineer, whereas the other developers are full-stack (but really they're all backend engineers).

The PR process is that you post your PR in the PR channel and someone should pick it up. I'm finding however that mine are being ignored, to the point where the scrum master has had to ask people to pick them up, though this hasn't really had any effect.

One reason could be that, as I don't know their backend language and am unable to contribute to a lot of other PRs, the other developers feel there is some inequity and might be a little resentful. However that seems childish to me and they should be aware of the reason for this.

Would appreciate any suggestions as I'm not sure how to continue here. I'm a senior developer myself and have worked with other teams just fine. But this team is significantly larger than my previous experience.