Strange behaviour of 1Password 8

I have installed 1Password 8 on both my iPhone and my MacBook Pro.

Since quite some time I receive from “hello@1password.eu” an avalanche of messages “New 1Password sign-in alert” informing me that

We've noticed a new sign-in to your 1Password account (...) on a new device. 
If this was you, ignore this email.

The message contains strange login addresses, all from Switzerland where I reside.

Further in the message there is a reference to the “Safari extension” and the advice to secure the account.

Following the advice I changed my login details, but to no avail, the messages continued.

Checking the web, I noticed that this situation was already discussed about a year ago at Reddit (https://www.reddit.com/r/1Password/comments/1af8jcq/new_1password_signin_from_safari_extension_email/) where a team member of 1Password labelled this behaviour a bug that they were aware of.

As it seems the strange behaviour arises when you empty the Safari cache on either the iPhone or the MacBook. In fact, I could reproduce this behaviour.

Since I didn’t have this situation in the months before, I guess that it was introduced by a recent update of 1Password 8.

Does anybody have a similar experience?

Another reader ran into something like this but it wasn’t reproducible. I mentioned it in passing here.