The warnings and what each button does

"Anna's keys do not match KUVRT's public key record." Sending to them is paused until you choose:

• "Compare the safety code": check it with them in person. This is the safe first step.
• "Trust the new keys": only if they told you something changed on their side. KUVRT first checks that the new keys belong to their KUVRT, and asks once more.
• "Block": stop everything from them.

"These keys come from another KUVRT." Setting up again keeps the same keys, so this is never Anna. "Trust the new keys" is not offered here: "Block" or "Delete chat and contact".

"KUVRT's public key record is inconsistent." Sending is paused in that chat. Compare the safety code with them, then tap "Continue anyway". "What this means" explains more.

"Someone may have added your KUVRT to another device": if that was you, tap "It was me".

If not, tap "Stop every other device", type your recovery phrase and confirm. Every other device is removed, your own too - link them again afterwards. This device keeps its chats. "Export your chats first" saves a copy before.

Short notes in a chat say when the other person added a device, set up KUVRT again or deleted their KUVRT. After "Anna set up KUVRT again", compare the safety code.

Compare the safety code