Changed sim still sends lost sms.

Hi.

I recently changed sim cards, but forgot to deactivate avast anti theft before I changed.
Since then every time I reset my phone, and also randomly, it sends a lost message to the first contacts phone.
I have read through the FAQ, on my phone used Avast to set the current sim to the safe list, and also sent an unlock command from the website to the phone to also add the sim to the safe list.
I’ve also tried uninstalling Avast and the anti-theft add on, but still have issues once reinstalled.

This issue is still happening though, any idea how to stop it other than not running Avast on my phone?

Cheers.

https://my.avast.com
Did you set the phone as found there ?

Tried that but it says it can’t connect to device.
Have since found that the box for allowing avast to send sms wasn’t ticked, now is, but still having the same issue.
Going to try uninstalling avast completely and reinstall, rather than just the anti theft bit.

Just in case you need it, here is the manual:
http://files.avast.com/files/documentation/mobile-security-user-guide-en-v2-4-updated.pdf