TLDR: Use a VPN before you do an add-on
I live in Australia and of late have had LOTS of small niggly issues when trying to install any add ons to kodi, sometimes it does the install of the app then fails on the depenancies, sometimes it sits there for a long time before it obviously times out.
After a LOT of buggering about and looking at logs, I saw errors as it tries to get files from ftp:\\halifax.nnnnnn So I did some more research on that avenue and deep down I found that it ‘could’ be the ISP here in Australia blocking the access, so…
Fired up the VPN, selected the good old US of A and fired up Kodi 21.1 and tried to install the same files I was having issues with…
THEY ALL INSTALLED !!
FYI my ISP is Optus
Hope this helps someone 