This topic has been created before:
https://meta.discourse.org/t/cant-verify-csrf-token-authenticity/25568?u=deanmarktaylor
I specifically mentioned this only occurs for mobile users for me:
https://meta.discourse.org/t/cant-verify-csrf-token-authenticity/25568/5?u=deanmarktaylor
I’ve also updated commented on stating my thoughts on why this happens:
https://meta.discourse.org/t/cant-verify-csrf-token-authenticity/25568/13?u=deanmarktaylor