[BUG] Does not work with ext:container and TYPO3 13.4.18+

[jacobsenj]

The issue is, that the copied elements, when inserted into a container element, do not get a correct tx_container_parent field value. The javascript code seem to set this on move only.

I'm running with this patch for the time being - only for use with ext:container

container.patch

[DavidBruchmann]

Thanks for the report, the IDs are indeed a major problem with several issues.
The colpos has to be part of the id too, else the elements are added to the wrong col if several exist.
According update is in work.