TYPO3 Core

We can confirm this issue as well. In combination with the issues of selectCheckBox minitems it seems not to be possible to use any checkbox (or radio) based control or single selectbox control with an eval=required.

The problem here seems now partially solved;

AFAICS the only validation still failing is:

Styleguide > Form engine - required > tab "Select" > "select_5 selectTree, minitems=1, maxitems=3"

There is another problem, which is the absence of text inside the "Review fields with failed validations" popover opened clicking on the "i" icon

Test repeated with TYPO3 13.1.0-dev (latest main)

Styleguide > Form engine - required > tab "Select" > "select_5 selectTree, minitems=1, maxitems=3"

the element shows the pagetree and allows you to select a maximum of 3 pages; you cannot check a 4th one

I guess that the issue can be considered solved