They use a high efficiency low thrust hall effect engine - for those kinds of thrusters you might have to run it continuously, possibly continuously to ballance out the atmospheric drag at low altitude. For normal chemical thrusters you indeed use the for just a bit very occasionally (or else you run out of propellant very quickly).

Still I agree it is fixeable - they can tune the hall effect thruster on newer sats to not radiate in this band & avoid running the thrusters when in the field of view of that one radio telescope at the times it is operating.

They're not running thrusters continuously except during orbital transfer. Otherwise they'd run out of propellant pretty quickly even with a HET, and operating smallsats at 559km doesn't require that much orbital correction. They probably fire them far more often for conjunction avoidance than station keeping, but again that's a reported 300 total manoeuvres per day across 8k satellites, which gives them a bit of scope to time them for when they're unlikely to upset regulators