Thirty-five years after “When Harry Met Sally…” asked the question of whether straight men and women can be friends without sex getting in the way, “Matt and Mara” rephrases it with more anxiously fraught social stakes — raising the accompanying and ever-relevant query of whether two neurotic writers should really fraternize with each other at all. The fourth feature from Canadian writer-director Kazik Radwanski is an itchy, unsettled and often poignant relationship drama, consistent with his previous works not just in shared personnel — notably lead actors Deragh Campbell and Matt Johnson, who also headlined Radwanski’s 2019 breakout “Anne at 13,000 Ft.” — but in a tingly, seasick storytelling sensibility that makes something volatile and cinematic out of ostensibly static material.

A decade or two ago, when the mumblecore movement was at its zenith in North American indie filmmaking, a trim, talky character piece like “Matt and Mara” — a highlight of this year’s...