Social stagnationism is a form of stagnationism which is directed against social progress. Social staganationists (SSs) have traditionally identified as "social conservatives", although "conservatism"'s litany of failures is beginning to make that term less marketable, and many SSs are now adopting other terms such as "politically homeless" (claiming to have been "abandoned" by the political left so they can attack it without being branded as "conservative").
Social stagnationists in 2020 or so tend to use phrases like "PC run amok", and may pose as left-leaning by using left-wing vocabulary and concepts (e.g. feminism, oppression) to attack leftward/progressive movements. Transgender rights are currently a popular target for attack (especially in the UK, presumably due to trans people having more rights there), just as gay/lesbian rights were 15-20 years ago.
They differ from social regressives in that their view of society may have been realistic within the past generation or so, whereas regressives want to a return to a time which they have received largely as a mythological narrative and which may never have existed.