contact import via vcf file to e.drive doesn't work

Summary

I have exported 780 contacts from my Huawei P10 phone via vcf export. Than I have tried to import this vcf file to my e.drive contacts. But nothing happens. I have tried the following steps:

1. imported the vcf file to my Evolution address book on my ubuntu laptop. All 780 contacts are imported.
2. Exporting the contacts from evolution into a new vcf file
3. try to import the new vcf file on e.drive -- only 80 Contacts are imported

Than I have tried this on my own nextcloud 14 server

1. Import of the original vcf file --- failed
2. Import the new vcf file from evolution --- 779 contacts are imported -- 1 gets lost
3. Exporting the 779 contacts from my own Nextcloud server into a third vcf file
4. Importing the third vcf file into e.drive ---- 228 contacts where imported

From another user from telegram group I know, that he have had the same problem. He have tried to import 200 contacts but only 100 where really imported.