Pliers - no Disarm prompt

[1-800-NOTHING]

happened on Camden at the train carriage objective.
two enemy plants, went for the closest one.
looked for the “Disarm” prompt at first (in order to initialize disarming via the Use key). then manually switched to pliers via the number keys.
no disarm prompt, and no disarm progress.
kept trying to find the right spot for some time, then blew up.