unfortunately, it reverted to a semi regular robe now... you could try to fix it by creating a mod but it's a lot of stuff to understand just for resistance to an unused damage type...
theoretically, it's just one line to add but you have to :
- extract the "shared.pak" file,
- convert the "_merged.lsf" binary file in the newly extracted RootTemplates directory to something you can read.
- find the line : <attribute id="Icon" type="FixedString" value="Item_UNI_RobeOfSummer" />
- add right after it : <attribute id="Stats" type="FixedString" value="UNI_RobeOfSummer" />
- convert back to binary again
- either repack into shared.pak or make a mod so it stays separate and don't disappear with the next patch (which could also fix the issue)...
if I understood correctly how it works, saving with this change in effect would revert the item but it's just a (self) educated guess... lots of hoops to jump through for a red dress