Copying any text in Libreoffice Writer inserts a ddlink bookmark in the document

Copying any text in Libreoffice Writer changes the document and inserts a ddlink type (with selected text) bookmark into it.

Gentoo x64, openbox, tint2, Libreoffice-7.4.4.2 and earlier, xfce4-clipman-plugin-1.6.2.

With Linux Mint XFCE (running in Virtualbox) уverything works as it should.

What could be the reason?