Why not "Tá argóint ag mo dheirfiúracha gach lá."?
The “every day” means that the arguing is habitual, so bíonn is used rather than tá.
Is a more literal translation "An argument is had by my sisters every day?"
No. The literal translation is "An argument is habitually at my sisters every day".
Would the reverse construct: "My sisters are habitually at an argument every day" be acceptable / convey the same meaning?
No. The subject of your suggested sentence is "my sisters are" - bíonn mo dheirfiúracha, a totally different sentence than one that starts with bíonn argóint.
What does Bíonn mean in this case
bíonn is the present habitual form of tá.
The gach lá tells you that this is a habitual thing, so you can't use tá X ag Y, you use bíonn X ag Y instead.
The hint is also terrible abd does not
The hint does not mention Bíonn perhaps an update should be included
The hint does not mention Bíonn perhaps an update is needed