Cannot add a phone to a specific contact

Nextcloud version: 29.0.9
Webserver: nginx/1.27.1 (fpm-fcgi)
Database: mysql 10.11.11
PHP version: 8.2.26
Contacts: 6.0.3

I was tried add a phone number to a contact using the web interface, but I always get the following error messag:

Unable to update contact

Then, I tried with WebDav client, Evolution, and after adding the email it shows the following message:

Cannot modify contacts: Failed to put data: HTTP error code 403
(Forbidden): Sabre\DAV\Exception\Forbidden
VCard object exceeds 5242880 bytes[exception][message]

I tried with other contacts, and I can add the same phone number to other contacts with no problem. So, I concluded that the issue was contact-specific. Then, I removed the contact picture and loaded it again. After that, I was able to update the contact. I guess that contacts have a maximum size. Am I right? Can I change that size? How can I see the size a contact is using on the application?

It looks like the default for vcard is no limit on a user’s picture.

Quick search:

But the applications will incorporate a limit, because that also makes sense with today’s cameras.

Not at all and no useful information IMHO.

That is 5 MB! Normally a vcard just contains text.
How did you assigned images to your contacts?

I don’t remember whether I added the image via the webpage or via a client application (like the KDE Kontact suite). Anyway, I have the issue when editing the phone field. The image was already uploaded, and it has less than 400 KB.

I cannot reproduce the issue now because I removed the picture, and loaded it again. Now, I can edit the contact via the Nextcloud web interface.

I know.
I suspect that there is a check on the size of the contact and if the contact is too large overall, then no changes can be made, whether number or image.