Please be aware of versions in .vcf, here is a search on the forum.
https://community.e.foundation/search?expanded=true&q=versions%20+%20.vcf
This is an old issue, Import contact result in "defective contacts" (#972) · Issues · e / Backlog · GitLab, but is still open. I do remember having to take action (some time ago!) to convert my .vcf to suit eCloud.
The most recent post (4 months ago) suggests this will still be an issue (for some).