Ten years of Acrobat Pro watermark presets disappeared

I stupidly, stupidly, upgraded from Acobat Pro 11 to DC, and now with a deadline looming, I find that all my saved watermark settings — some ten years of different watermarks that we use — have disappeared. Wiped, I presume, by the sack of sh*t that is Acrobat DC.

I am unable to find even where my original PDF watermark settings were stored by Acrobat (somewhere in my user Library, but God knows where).

Does anyone know how I can locate my old Acrobat Pro watermark settings / preferences (whatever) and import / transfer them into this nightmare that is DC?

I'm using the lastest version of Acrobat Pro DC in MacOS 10.15.7.

Thanks for any help.