Problems with new shoppergroups

[ermes]

Hi forum, on an installation of virtuemart 3.8.4 10335 (Joomla 3.9.21) i have a issue with the creation of new shoppergroups. When i click on the green button "New" in shoppergroup list, the form is filled with the default shoppergroup data (COM_VIRTUEMART_SHOPPERGROUP_DEFAULT) and if i try to modify an existing soppergroup there is same problem. Obviously if i delete this datas and set new datas, when i save, the system overrides the datas of default shoppergroup.

How i can resolve it?
Thank you in advance!

[UPDATE]
This scenario happens if i have set a shoppergroup on the admin user that i use. Infact i changed my shoppergroup and the previously scenario repeats but with the data of the shoppergroup that i have set on my admin user.

[UPDATE 2]
This not happens on VirtueMart 3.8.9 10473

[AH]

Resolve by updating VM (oh and joomla as that is also out of date)

[ermes]

Resolve by updating VM (oh and joomla as that is also out of date)

Yes i know that joomla and vm are out of date but i have to update before a lot of extensions on this web site