Soma smart shades 2 is not discoverable

Hi,
I have 4 Soma shade2 controllers. They were installed by previous owner and are likely 5 years old.
The batteries were not charging via the solar panel.
Could not buy a new one, as they are out of stock and superceded by soma smart shades3 and are not yet available in Australia.

So I replaced the batteries, but now they are not discoverable. What should I do to get them reconnected to the app?

Any help would be appreciated.

Regards, Saran