Yeah, for sure. I've been a commie since I was 13 so when I went to university and grad school I was already a self-avowed Marxist, which was my first exposure to other people who'd actually read Marx and took it seriously outside of the internet. In the real world the only politically engaged people I was around were liberal socdem types or anarchists (I am working class poor so my environment was largely punks who'd took the ethical aspect more seriously), I was always a cantankerous crank for my opinions but still tolerated well enough (this was around the mid-2000's).

In academia, potential theorists are fair game for anything, and radicalism has a definite chic. There are not insignificant minorities of humanities and social sciences professors who "deploy" (pick at random what seems interesting or useful) Marx and other Marxists in their critique and analysis, and a slimmer but still real minority who would explicitly call themselves Marxists. There are a cluster of figures with greater or lesser import that you'll see come up frequently in academic papers and social science journals who are Marxist icons or who were card carrying communists: Marx himself (Engels almost never), Gyorgy Lukács, Antonio Gramsci, Louis Althusser (figure these as group A, theorists who were actual members of communist parties), and then contemporary cultural, literary or critical theorists who claim affiliation with Marx (Alain Badiou, Fredric Jameson, Slavoj Žižek), lastly what I'd classify as Marxist fellow travellers or revisionists (Herbert Marcuse, Theodore Adorno, Walter Benjamin). The academics may go to protests, they may organize or attempt to, but many will not, or the extent will be within their university politics or faculty unions.

Comparatively, in activist circles for the longest time Marxism and communists were a fading star that had been diminished by the fall of the Soviet Union. If there were local or community events you might get one or two old timers who were avowed Stalinists, cranky or eccentric older dudes who carried the flame. That started changing in the mid 2010's such that Marx saw an increasing resurgence, and with it explicit communists and people providing apologia for actually existing socialist states (in my opinion as much as the financial crisis was responsible, the failure of Occupy Wall Street as a moment and a movement, and the shortcomings of its tactical orientation and practice was what paved the way for the resurgence). Whereas academic Marxists do not touch Michael Parenti, for example, he's a crucial figure for people doing actual organizing and local work. The same goes for a serious engagement with the works of communist leaders -- Lenin, Stalin, and Mao are much more influential theoretically and philosophically for practicing communists than any of the theorists above, whereas outside of history departments covering those areas, Lenin, Stalin or Mao do not get "deployed" for analysis or critique at all.

There are of course points of overlap (I guess myself being one, but I'm no longer in academia and I only started becoming actively involved in the communist party as a working class schlub), and this is my own limited perspective from my own academic and national context (Canada), but that's my attempt at summarizing the main differences. The former are going to write papers and whatever they say their politics is, 9 times out of 10 they're actually succdems. The latter might not be reading as much theory, but they're doing the real work of building a movement.