This has been brought up in the past. I don’t know if there was ever a resolution, and I don’t use Apple devices, so I can’t check.
My only advice would be to to check your theme settings. Try light mode, dark mode, and try with and without the “match device theme” option selected.
Also try uninstalling your app, clearing the browser cache, and then reinstall the app. I’m guessing it has something to do with mixing light and dark themes at some point.