Is it possible to retrieve Missing Blending/Effects from my personal CC Library 'Styles Group'?

I've been using CC / Photoshop since (I think) 2017. All Styles have been created in Photoshop over the years. I store the Styles in my personal CC Library. The Library is not shared with others. I recently went into my 'Styles Group' in CC and found the majority of Styles are not nothing but empty gray squares with no assets/attributes/blending. The Styles that are not 'Empty' appear normal and complete in the Library, but once applied, the blending modes are not being applied and not showing in the Photoshop Effects Options List. And, yes, when saved, the save with blending modes is ticked. Do I just need to accept that the Styles are gone? Or, is there a way to retrieve the data? Every other Group in the CC library is intact with nothing missing.

Fortunately, I have backups of everything ever created.  ...However, ...!

And, I'm just whining now... The files are backed up in a number of external drives that have been used over the years. Some of those files / drives date back to CS5. (Yes, you are right, I need to consolidate everything onto newer, bigger and better drives.)