Sitemap.xml auto generating with undefined values

Hello
I still can’t understand the logic, but somehow, the webflow is publishing invalid sitemap entries, with undefined instead of the name of the cms collection.
Example

https://myurl.com.br**/undefined/**oferta-internet-fixa-em-aparecida-de-goiania

At first 800+ pages with the same error.
After a long search on the CMS and Webflow Pages options, there is no incorrect parameter under first analysis.
The page is generated correctly for a specific collection, but what bothers me is this definition of undefined, which for me does not make any sense until now.

What could be the reason for this? How to solve this issue?

Add sitemap example please (hard to answer like this). This issue happens only in one of your sites? This issue related only to CMS pages?

Sitemap links of two sites with the same issue
https://www.timliveinternetfibra.com.br/sitemap.xml
https://www.timlivepromocao.com.br/sitemap.xml
This issue related only to CMS pages.
I’m not sure what the cause is, they are collections with 2000+ entries, one with 6000+, that seems to create a duplicate record, one with the correct url set in the collection and the other with undefined.

Did we find anything here?
We are facing a similar issue,

https://www.peoplehum.com/sitemap.xml

sorry about the late answer but not at all, the undefined has causing us google search console problems since them. if someone has a solution please help!