Unable to update phone number in my.avast.com

I bought a new phone recently, using same SIM. Avast anti-theft worked fine on old phone. I deleted old phone from Devices in My.avast.com and added new phone. However an incorrect phone number was detected and could not be changed in settings. Think this was the phone number hard coded on SIM by service provider (which I never used), not my usual number I had ported from earlier provider.
I requested a new SIM with correct phone number. Uninstalled all Avast apps, deleted device in My.Avast. Reinstalled everything from scratch. Now phone number in my Avast account is blank. I can enter and save the correct number, but on re-entering settings screen, phone number is again blank.
The impact of this is that remote anti-theft functions only work if mobile data is enabled. If data disabled, device is not found in my.avast.com. So SMS commands to sound siren, lock phone etc. cannot be sent to phone via mobile network.
Effectively, anti-theft is useless if correct phone number cannot be updated.

Updates in your avast account can take several hours before they show.

I suggest to :

  • remove anti-theft
  • remove the phone from your account
  • wait e.g. a day
  • install anti-theft
  • connect the phone to your account.
  • wait a day and see if everything is correct

If things still don’t show up correct, contact avast (ticket) > https://support.avast.com

I tried the above suggestion but still having same issue after reinstalling.
I can enter my mobile number and save it (according to success message) but on checking again, the number is no longer there.
The remote anti-theft functions work only if mobile data or Wi-Fi are switched on.
Unable to send commands via SMS so anti-theft is effectively useless as it can be disabled by switching off mobile data and Wi-Fi.
Unable to open a ticket as I’m using free version.

It doesn’t matter if you are using the paid or the free version, everyone can open a ticket.

The button to contact an agent is only available on the website for paid products.

https://support.avast.com/support/tickets/new