Steps to reproduce the behavior:
Expected behavior
To login and edit where needed.
Which versions of Sanity are you using?
@sanity/base 0.140.9
@sanity/components 0.140.9
@sanity/core 0.140.9
@sanity/default-layout 0.140.9
@sanity/desk-tool 0.140.9
What operating system are you using?
iOS 12
My settings for Safari allows cookies

Haven't heard anything back on this yet? Can someone please look into it please? Quite frustrating that it's not working as a big part of the reason moving to Sanity was that I wanted to edit content on my mobile.
Thanks!
Thanks for the report and apologies for the radio silence. We're aware of the issue. It seems that our login at times triggers the cross-site tracking prevention in Safari (even if no such tracking is going on). It's a sporadic error, but once it strikes it's sticky and prevents login.
We will definitely be addressing the issue. The immediate remedy is to allow cross-site tracking.
Thank you for the quick reply @evenwestvang and for addressing the issue! Have allowed cross-site tracking now in Safari and is working nicely, so am happy until this can be looked into. 馃憤
Are there any updates on this?
Looks like the latest version of content studio is not letting me login via Safari - looks like a cookie issue? (404) https://lx67wdtx.api.sanity.io/v1/auth/testCookie

This proves to be a complex issue to handle, but we are working on it! Stay tuned.
Thanks @kmelve, appreciate that. Good to hear you're still on it 馃憤
Was able to get around this in Chrome Beta by turning off the "Block third-party cookies" option in settings. Need to do this each time I want to login (since I don't plan on leaving it disabled for general browsing).
any news on this?
This doesn't happen for me anymore in the latest Safari 14 for macOS Big Sur. 馃コ

But still happens for apps (here Panic's Nova editor) using WKWebView.

Most helpful comment
Are there any updates on this?