Deprecated fields tab grid looks weird

[Siedlerchr]

With the following entry I get this layout in deprecate tab:

The problem seems to be that because primaryclass and archiveprefix are text fields they each get 50% of the height and that however the combobox month selector can not be scaled that way, too

@Article{Testa,
  author         = {Sam and jason},
  title          = {Test},
  journaltitle   = {Test},
  year           = {2012},
  date           = {2016},
  msbib-accessed = {2015-12-12},
}