At User Icon > Backgrounds, the "Hide Locked Backgrounds" switch is on the left of the modal. It should be in the centre:

Hi
I would like to work on this issue .Please allow me.
@himanshus852 Thank you! Please go ahead! Post here if you have questions or run into trouble.
The person who originally reported this, @Zarathustrik, has posted to the Report a Bug guild again with some extra details that they've just noticed:
_"there is some problem with this bug in " Hide locked backgrounds". I reloaded my page it appers again, I reloaded again it disappears, then I reloaded again and it appears again. There is something starnge with this floatint bug, Thank you"_
From my testing just now, it seems to depend on which page you were looking at before going to the backgrounds. Here's one way to reproduce the bug:
There may well be other ways to reproduce it.
@Alys labels ;)
I was about to ask for this one and saw that someone had claimed it but it was still marked Help Wanted
Can I work on this issue?
Hi, I saw this issue open and decided to give it a go, and I think I have it fixed.
I can proceed to pull request if it's okay.
@anshuman9999 @ivan-suarez This issue is labelled as "in progress", not "help wanted", so it's not currently available to be worked on. See "Ways to Help" in Guidance for Blacksmiths for more details about selecting issues and the label system. :)
@himanshus852 How are you going with this? Do you still want to work on it?
@himanshus852 Since you haven't replied, we'll make this issue available for others to work on again.
@thewilloftheshadow Since you were the first other person to inquire, are you interested in taking this up?
Hey @shanaqui! I've actually promised myself I wouldn't work on anymore frontend jobs right now because they always frustrate me and mess up my day. Sorry about that!
Hi! Can I take this one?
I dont mind acting as a backup if this ticket frees up after @yiqcheng98
Hey, can I work on this issue?
Sorry for the delay everyone, I'm assigning this issue to @yiqcheng98 if you still want it!
If he doesn't accept can I take it then?
If @yiqcheng98 isn't interested I'll go in order of who posted before but since @SachJay already has an assigned issue that would be you :)
Okay
I've been playing around with when this bug occurs based on @Alys's comment above, and I think I've figured out exactly how to reproduce it. Maybe this will be helpful to whoever works on it.
I went to every subsection of the Habitica website (Tasks, Items, Equipment, Market, Quests, Party, etc.) all the way across the bar, except for the Help tab, because those subsections lead to different websites (except Report a Bug and Habitica Help).
There are some sections that always misalign the toggle, whether you refresh the browser or not. These are Tasks, Items, Equipment, Stable, and Market.
All other sections (Quests, Seasonal Shop, Time Travelers, Party, Tavern Chat, My Guilds, Discover Guilds, Group, My Challenges, and Discover Challenges) will correctly center-align the toggle if you refresh the browser.
However, moving from any page that center-aligns the toggle to any page that left-aligns it will always "reset" the alignment back to left-aligned. For example:
So basically, whenever you visit a page that left-aligns the toggle, all pages thereafter will also left-align it until you refresh. Once you refresh, all pages that center-align the toggle will center-align it until you visit one of the pages that left-aligns it.
Hopefully this makes sense and is somewhat useful! Good luck!