"Open Terminal" missing its Oxygen icon

[Void1 <Void1@comcast.net>]

    Dear Maintainer,
    In the Dolphin toolbar, the "Open Terminal" action is missing its
    Oxygen icon.
    (This Dolphin icon is present in Debian 10, but is missing in Debian
    11.)
    
    I verified that the Debian 11 "utilities-terminal.png" icon is
    installed by the "oxygen-icon-theme" package (similar to Debian 10).
    So it appears that the issue is with Dolphin, not the
    "oxygen-icon-theme" package.
    
    To reproduce:
    Fresh install of Debian 11.2 with KDE
    Konsole:
      su -
      apt update
      apt install --yes plasma-theme-oxygen oxygen-icon-theme
      reboot
    System Settings->Global Theme->Oxygen 
    Restart
    Dolphin->Text Position->[CHECK] Icons Only
    Dolphin->Configure Toolbars
      Move "Open Terminal" from "Available actions" to "Current actions"
    
    In the Dolphin toolbar, "Open Terminal" is missing its Oxygen icon.

    I checked that the Oxygen Terminal icon was present in the
    filesystem:
      su -
      apt update
      apt install --yes mlocate
      updatedb
      locate -i oxygen | grep -i terminal | grep -i png
    /usr/share/icons/oxygen/base/128x128/apps/utilities-terminal.png
    /usr/share/icons/oxygen/base/16x16/apps/utilities-terminal.png
    /usr/share/icons/oxygen/base/22x22/apps/utilities-terminal.png
    /usr/share/icons/oxygen/base/32x32/apps/utilities-terminal.png
    /usr/share/icons/oxygen/base/48x48/apps/utilities-terminal.png
    /usr/share/icons/oxygen/base/64x64/apps/utilities-terminal.png
    (These search results are similar to those in Debian 10).
    
    Since the icon is present, it appears that the issue is with
    Dolphin.
    
    Please fix this issue.
    Thank you.