I synchronize 1800 addresses via nextcloud to two PCs. I use Thunderbird with CardBook. Most new addresses or changes are synchronized, but there are new addresses that do not appear in the address book of the other PC, but the number of addresses is identical. And there are addresses whose changes are not adopted. What could be the reason for this? How do I find the error? How do I see in Nextcloud how many addresses are in the address book?
I am working with Nextcloud 12.0.2, Thunderbird 52.5.2 CardBook 25.6 One PC is Windows 7, one PC Ubuntu.
Thanks for advise