Maybe blog sample data installation should be fixed so that it makes sure that the menutype values are unique, like we do it elsewhere for aliases when saving copies. This would for sure solve the (absolutely valid) scenario described in the issue, while increasing the length will only make it less likely happen.
I think we only have to modify the blog sample data installation so that it uses only a substring of the translated language string which is short enough so that the language code always can be appended without exceeding the limit of 24, then we can be sure we don’t have the same value for 2 languages.
joomla-cms-bot
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https://github.com/joomla/joomla-cms/blob/4.3-dev/administrator/components/com_menus/forms/menu.xml#L20
There is a maxlength for the input field which should be increased.
But I am not convinced, Every limitaion is a limitation and an automatically generated unique menuname could be a better solution.
Suppose for example hungarian and write a menu title like this in english.
en: Disability equality laws
Hungarian translation i > 48
hu: A fogyatékossággal élők egyenlőségére vonatkozó jogszabályok